Legal Question in Wills and Trusts in California

No, but it might be wise to record it ASAP. If something should happen to you, by having a recorded deed granting a life estate, your mother would have legal protection against those who might wish to evict her.

I'm assuming that by using the term "filing" you mean recorded. Documents transferring interests in real property are recorded at the county recorder's office in the county where the real property is located. There is no time limit for her to record, but she could lose rights if something happened to you and there was a dispute over title later on with third parties.

Grants of interests in real property are valid and enforceable as soon as delivered to the grantee. However, intervening interests that are acquired without notice may supersede the grant. This is why recording is important, because recording in the County Recorder's office in the county in which the property is located, is binding notice to the whole world of the grant. Until the grant is recorded, other parties must have actual notice.