If you trust her, respect her competency, and know that you are resistant and that keeping all this emotion pent up is painful to you (it seems you have already recognized that you have maternal transference feelings), then I would go for it. That said, I think her phrasing was awful, and I don't know that it's ever a good idea for a T to directly encourage a transference. I think it should be supported and very carefully handled, but the research suggests it be nade explicit only after the developmental tasks it enables have been experienced.

I think its FAR more advantageous to have a client learn to accept the fact that a parent, etc did not love them in the way they needed to be loved. "Love" from a therapist will NEVER come within a million miles of being comparable to parental love. Ever. Its ludicrous to even suggest the notion.

Accepting the loss and also filling the void are not incompatible. You're right that love from a T will never be comparable to parental love, but it can fill in the developmental gap that the absence of such love created. But it takes a very skilled T to do so, and wouldn't be applicable to all clients. There is a sizeable body of research which explains how this can be accomplished. It very much worked for me.