I don't think so! But I could be wrong. The only time I've heard of an adult initiating into a chapter is like if a local becomes a national.
Like we recently added a new chapter to Chi Omega. When they initiated the girls they invited their advisors and some alum to become newly initiated members of Chi Omega as well.
Other than that, I don't think your mother would be a legacy.
Someone correct me if I'm dead wrong (weirder things have happened)

Hootie
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What do you get when you cross and Alpha Omicron Pi and a Sigma Phi Epsilon? A beautiful Chi Omega!!!
[This message has been edited by Hootie (edited February 28, 2001).]