Mary Cheney has decided to wade into Indiana's fight over whether to adopt a constitutional ban on same-sex marriage, hosting a reception in Indianapolis on Dec. 11 to raise money for opponents of the amendment.

The move comes as her sister Liz Cheney's position on gay marriage and the family's internal feuding over it hang over Liz Cheney's 2014 Senate campaign.

Mary Cheney, who is lesbian and married with two children, has publicly clashed with her sister over the issue of gay marriage in recent weeks. Liz Cheney is running in a primary against Sen. Mike Enzi (R-Wyo.) and has declared she opposes same-sex marriage.