Why don't you ask her? I know that probably sounds scary, but we're not psychic and neither are you -- she's the only one who can tell you what she's thinking. Tell her you'd like to try a relationship, see what she says.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.