Mine are the same age, 4 in a couple of weeks.
One twin wants to be dry at night and sometimes leaks if he's not been to the toilet before bed, or wets if he gets up and goes to the toilet, but his pull up is wet so he takes it off but doesn't wake us for a dry one or put one on himself. The double bedding works brilliantly in these instances.
The other isn't anywhere beer being dry at night so we're leaving her until she wants to be dry.
With our son, I've told him if he's dry 2 nights in a row I'll let him try without pull ups. He always manages the first night but never the 2nd!
I struggle with the idea of making them strip the bed etc themselves when they are still so little. To me it's just shaming the child and I worry that creates more problems than it solves. But I appreciate making them do the work works for some.
As your problem is your dd is refusing to wear a pull up, I think you need to work out why. Mine don't care what design they wear as long as when I buy huggies ds2 wears the blue and dd2 wears pink (I try and avoid them for this reason).
So, does she get to choose which ones she wears? Could that make a difference? A star chart with a reward that she really wants for a week of wearing them all night - dd2 had a sticker album with a sticker for every time she did a wee in the potty during training as she was very reluctant to say train.
Definitely onesies back to front, even big girl knickers over the top so they're a little more snug might help.