No advice here unfortunately, I was carrying her right up until the last minute in my last trimester 😅😂
My son is almost 3, there's no way he'd want to stay seated while being outside. He started preferring to walk on walks around 2 years old.
Keep her clipped into the stroller. Get a clip cover if she is unclipping herself. If she's climbing out, it's for her safety, yours, and baby's. If she fusses, just head back for home. I've definitely had kids that didn't want to sit in the stroller, but they stay clipped in until I know they'll come back when called. Offer water and a healthy snack. Bring a toy. You can't be carrying her in a few months....