Steve223
Have you stopped to look at your moms side of the situation???
How old is your mom?
What was it like in her generation to talk to discuss any type of lifestyle that wasn't heterosexual?
Does she understand bisexual lifestyle?
Have you explained it to her?
Had she read any literature about it?
Etc. Etc.

What you might be asking her to grasp might be beyond her scope. So yeah I think you need to give her some time to educate herself, to become familiar with it & maybe you can ask her if she has any questions.
She's WORRIED! Every mom worries! It's our job. Whether it's about sex, school, career, anything! Moms want the best for their kids & we don't wanto see them suffer.
I think you're lucky your mom seems so willing to openly discuss this with you....give her a break.