Two weeks ago, my 14-year-old daughter was too tired to get up for school, and I told her to go back to sleep. I went downstairs, informed my husband she’d be staying home and said, “Another parenting decision brought to you by cancer.”

Tired for my daughter is not the same as tired for another kid. She had major surgery to remove multiple tumors in her belly in December and was still recovering. Soon after, she started radiation to treat two tumors in her right lung.

She can sleep in.

My daughters are 11 and 14. Over the years, I’ve thought about, talked about and probably bought a book about every major parenting issue under the sun. I’ve obsessed over table manners, screen time and vaccinations, worried that my kids were over (or under) scheduled and have been driven to distraction by who might think I’m a bad parent.

That all stopped Aug. 25, 2012, when I took my daughter to the emergency room for stomach pain. I was sure her appendix was about to burst, but a CT scan revealed something far worse — a giant tumor the size of a grapefruit was growing on her liver.

My daughter, then 11, was supposed to start sixth grade the next week. Instead, she was hospitalized for 40 days while they attempted to diagnosis her specific rare form of cancer (via two biopsies) and placed a Broviac catheter into her chest.

There are no parenting books that tell you how to explain to your child that she might die. We wanted to say the right thing without destroying hope. In those early days, we never talked about death. Instead we talked about going home, getting better. We urged her to eat, but her stomach hurt and she was depressed. Eating made her feel sick; nagging about it upset her. Every morning she stepped on the scale, and each time her weight went down, she looked at me and said, “I’m sorry.”

A few months later, I was at my gynecologist’s office, waiting for the exams that would clear me to be my daughter’s live liver donor. (She ultimately received a liver from a cadaver donor.) Surrounded by pregnant women and new mothers with tiny babies in the waiting room, I felt exhausted and numb. I imagined that they were all looking ahead to the birth of their babies, to the next milestone, to the first full night’s sleep in weeks. I closed my eyes and wished I was at the beginning of it all again. If I got to do it again, I would enjoy every single moment. I swear I wouldn’t look ahead.

After that day, I became a more laid back, permissive parent in many ways that extended to both my kids. It’s been nearly four years since cancer planted roots in my family. I think it’s safe to say we are all now permanently altered.

Things that once seemed big and important barely register on my radar. I thought I’d be fretting over when to let my daughters watch an R-rated movie, how late they’d be staying up at night (or out at night) and when they’d be tempted to drink alcohol or smoke cigarettes. It is a bitter irony that I don’t have to worry about my daughter trying alcohol because she can’t drink — not ever — or she risks losing her transplanted liver.

Being more permissive hasn’t necessarily made parenting any easier. The constant anguish of not being able to help my older daughter — to stop her pain and ease her fear — makes me want to move mountains for her. The constant guilt of focusing on her sister’s illness drives me to spoil my younger daughter (sometimes to the point of exhaustion). Even when your kid is desperately ill, you still have to be a parent. You still make mistakes.

My older daughter was mad at me the other day, and I was mad at her. It was something stupid, an argument driven by teenage eye rolling and my own impatience. We were in the car, and as we stopped at a light, she stared up at the sky and asked me if I thought people could visit the clouds after they die. I knew she said it because she didn’t want me to be angry. She was reminding me, in her way, to stay in the moment.

“There is a place,” I said, “where I believe we go after we die. It’s not here and it’s not in the clouds. It’s somewhere …other.”

I hate that my bright, beautiful teenage daughter thinks about dying every single day. I hate that I didn’t say, in that moment, that of course we could visit the clouds.

I’m a different mother because of cancer. I’m sadder, but more present. I let certain things go that I probably shouldn’t. (You want to eat in bed? Sure!) I often drive my younger daughter to school so she can sleep in a little later. I don’t nag her (too much) about homework or cleaning her room.

My daughters are different children because of cancer. They’ve had so much taken away from them — birthday parties spent in hospitals, days and weeks of the family being split up because of treatments and surgeries. They’re not perfect kids, but they are compassionate, respectful and wiser than their years. They aren’t spoiled — my older daughter frets about money and is quick to say thank you when she receives gifts from friends and family. My younger daughter is quick to give hugs and loves spending time with me. They are becoming the young adults I dreamed about back in the days when I had the luxury of reading parenting books. They are doing this in spite of my over-indulgences.

I spent the first 11 years of motherhood worrying about doing everything right so that I could raise productive, happy, high-functioning adults. Now, I worry about how to get through today and how I can possibly survive tomorrow. On good days, I dream about my girls growing up together and having their own kids. In this dream there is a cure for childhood cancer — for all cancer — and neither they nor their children worry about anything more terrible than dealing with a high fever or a scraped knee.

Today I was chatting with another parent whose kids are 9, 5 and 1. He told me that his parenting style has changed with each child. His first child got the brunt of his parenting worries, as firstborn children often do, but like me, he now lets a lot more things go — sleep training, eating solid foods, making the first day of kindergarten perfect. It occurred to me then that maybe it’s not just cancer that has shaped my parenting style, but time, and age, and retrospect. Maybe I’ve stopped obsessing over every nuance of my kids’ lives because I am witnessing firsthand how quickly childhood goes by. I am a parent of a child with cancer. But I am also just a parent.