If my mother puts her house in my name and has a life estate (she can live there until she dies) is it taxable to me?
No. A gift is never taxable to the recipient of the gift.
Technically, you mother is required to file a gift tax return, form 709. "Gift
Tax" is somewhat of a misnomer. Even though a gift tax return may
be required, very few people ever actually pay federal gift tax. The purpose of
the gift tax return is usually only to document a reduction in the allowable
estate tax exemption.