I sooooo know how you feel. My gf is also married and employed with a young child, as I've probably mentioned, and it can be damn hard to get a hold of her. Heh, she was like that before the kid though, she has ADHD and it's just very difficult for her to keep track of communications, who she's responded to and who she hasn't, whether she's charged her phone or even brought it with her etc. But the kid has made everything 5x harder, no doubt. Sometimes I don't even know how she and her husband function, their life seems so overwhelming so much of the time.
I've just had to learn that it has nothing to do with me, and that I can just ping her another way (email, quick call) if it's important and she won't be annoyed. Sometimes a single text really is too much to ask, and it would be whether it was me, her mom, her best friend, or even her husband who had sent it. Realizing that, by watching her with others, really helped.
If you're feeling antsy, why not go out on your own, join a meetup group, contact an old friend, something like that?
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.