Help! 2yo takes off nappy at nap time

[WaitingWaitingBaby2]

My 2yo daughter is perfectly behaved with her nanny 3 days a week and a terror with me. I understand this is all about her feeling safe/comfortable with me and letting it all hang out.

Problem is that she recently started to mess around/sing/chat in her cot instead of her nap (usually 12.30-2.30) and has found a way to take her nappy off. So I end up having to monitor her closely otherwise she'll wea the bed or worse.

How can I get her to keep her nappy on?? She can undo poppers, take off trousers and knickers, and I even put her in a sleep suit backwards which she got out of. I think she's bored/attention seeking rather than any aversion to nappies as its the only time she does it. And only when I'm looking after her.

Help!!

Gaffa tape.

When I had a little girl who started this at the same age, I found sleepsuit that only had poppers at the top half (it had a skirt thing on it), I put this on backwards, so that even with pulling the poppers open, she could not get the sleepsuit down her arms and off her body, so no access to the nappy. A few naps later, and the fun was lost and she stopped!

Thanks so much @willitbe that's so helpful!

Does she wear a sleeping bag? Put it on with the zip at the back. How about a sleeveless cotton leotard then back fastening popper onesy?