As the executor of [my mom's] estate, I'm trying to help her decide what to do with the house. Let another family member live in it who couldn't pay rent but could help with upkeep? Rent it out for market value? Or sell?
If she hasn't already, an article in The LA Times titled “Consider tax implications when downsizing,” recommends that she needs to hire an experienced estate planning attorney who can help her evaluate her options.
If she sells, she could possibly be in for a shock because there might be a considerable capital gains tax on the sale. Federal law permits a set amount of capital gains on the sale of a primary residence ($250,000 per person) to be excluded from income. However, anything above that amount would be taxed heavily as a capital gain.