Button Issues

Lily will not leave her belly button alone (sticks her finger in it and fiddles constantly) so I have been freezing at night so I can put her in these warmer pj's with no button access. In fact Nathan and I have to tell her (No button) all day long. I don't want to spend money on onsies and I never understood why they made them in her size until now and I might just have to get some as you can see below.

Normal yet slightly rounded by finger button.

Button that is clearly making it's way out