Legal Question in Real Estate Law in California

No, the best way is to do a quick simple will. If there is more than $10,000 equity in the house, it will trigger gift tax if she gives it away while alive. It will also have a disadvantaged tax basis for capital gains when your step daughter goes to sell it. If it goes to her by will, the basis will be stepped up to the market value on the date her mother dies, meaning capital gains will only be due on appreciation above and beyond that amount.

Probably not. Depending upon her competence and willingness to deal with this kind of stuff, better choices might be:

A living trust (avoids both probate and taxes);

A regular will (avoids taxes but probably not probate);

A holographic will (same as a regular will, but does not require witnesses or other formalities; the maker simply writes it out in her own handwriting, then dates and signs it).

Doing nothing at all might even be a better alternative than deeding away the property. Under the laws of intestate succession, your stepdaughter is likely the sole heir under the facts you give and will inherit everything anyway. However, there could be a more cumbersome probate process.

Don't use the deed process unless you have expert advice that for some unusual reason this is a better idea under some special set of circumstances.