Dear Bob: Thirty years ago my husband and I made a joint will. Now, after five years as a widow, I want to change the will. But I was told not to make a new will because the first one overrides the second one and that I cannot sell my home before my death. I want to sell to a family member, but I have a lease on my home until my death. I am old and want to know what is best to do without having to hire an attorney.

Ida W.Leesbury, Va.

Dear IDA: Every property owner should have an up-to-date will. If your will has not been reviewed by an attorney since 1977, it probably isn't taking full advantages of tax-law changes made by the 1976 Tax Reform Act.

I don't know why you don't want to talk to an attorney. Such a visit could be very profitable for you. For a minimal cost, perhaps less than $100, he or she will review your current will and recommended any changes.

Your letter indicates you may own a life estate, not a fee simple, in your home. If so, you can sell only the life estate and not the entire fee. It appears whomever is advisiong you is giving you bad advice. Only by visiting an attorney can you get accurate information to give you peace of mind that you've done the right thing.

Dear BOB: Since the 1978 tax bill raised the long-term capital-gain exemption income averaging of such capital gains? Burton M.,Rockville.

Dear Buron: No. Long-term capital gains are still eligible for income averaging. Your tax adviser can explain the details.

Dear BOB: Next January we plan to sell our home. Should we put a new mortgage on it now before interest rates go higher? Ray E., Woodbridge.

Dear RAY: No. It is the buyer's responsibility to arrange his or her own mortgage financing, usually with the help of the realty agent handling the sale. If you put on a big new mortgage now, you might find out the buyer wants to pay all cash-or perhaps can get better mortgage terms from another lendr.

It's true that the bigger the existing mortgage on a home. But it rarely pays to put on a new mortgage just before selling the property. Talk it over with your realty agent for more information.

DEAR BOB: Are "realtors" the same as "realty agents?" Rogers R.,McLean.

DEAR ROGERS: All realtors are brokers, but not all brokers are realtors. A real estate broker can elect to become a realtor (a member of the National Association of Realtors) by subscribing to a code of ethics and joining the local board of realtors.

But many brokers don't become realtors, for various reasons. Some excellent brokers are not realtors, although superior brokers are usually realtors. I use the term "realty agent" to include brokers, realtors and licenses real estate salespeople who work for brokers.

DEAR BOB: I talked to my agent about getting an FHA home loan. She said that with the current 9.5 percent FHA interest rate and a $60,000 maximum FHA loan, these mortgages aren't competitive any more. I hoped to get such a loan, as I have little cash for a down payment. Herb G., Rockville.

DEAR HERB: You're right. In many communities, FHA mortgages are no longer attractive. The maximum $60,000 mortgage is too low and the loan fee points (paid by the seller) are too high.

DEAR BOB: The city may rezine my residential property tax? Hector M., Falls Church.

DEAR HECTOR: As a general rule, change of zoning from residential to commercial makes your property more valuable. Of course, there are exceptions. State law determines if such a zoning change could result in reassessments. Before deciding whether or not to fight the zoning change, talk to city zoning and planning officials as well as to your attorney.