Hand Sucking

So baby girl has mastered finding her hands and is obsessed with sucking on them. I know this is a normal developmental step but also don’t want her to turn into a thumb sucker. She hasn’t done this yet, really just chews on her knuckles. Any thoughts on how much of this to allow. Sometimes we’ll swap her hand out for paci when we notice her doing it. Should we keep doing this or am I just overreacting and should let her do her thing when it comes to chewing on hands