My mother has poison ivy would it be safe for her to come in contact with my 1month and1week baby?

Yes. Poison ivy/oak/sumak are all reactions to the material from the plant that can cling to the skin surface and be spread by scratching.Blisters take ~18hrs to come up but itching may start sooner, so you can spread it on yourself.Patches related to the initial event may come up at different times.Washing removes the material & stops the spread. The "juice" from blisters does not spread it either.
Safe. The contact dermatitis by poison ivy on your mother is not a contagious condition!