Tell her

"What's new with me?" you repeat, faux-absentmindedly. "Not a lot. I've been studying. Getting ready for exams, you know. I recently figured out I'm into women, so that's something."

Liz perks up. She tries to look calm, but you recognize someone trying to disguise their interest. "Oh really," she says. "That's interesting. When did you realize?"

"Really recently," you say.

Liz smiles with motherly warmth. "Well I'm glad you've realized that about yourself. And so young, too! That's what's great about you girls these days, you aren't afraid to be bold." She runs an elegant hand through her short dark hair. "I was nearly thirty and already married to Emily's father the first time I was with a woman."

Thump goes your heart.