Thatīs alright
We know Snape is a good guy. He would be grumpy in public but caring in private XD
You can play anyone you like. So I take over Lupin for you.
Now how do you like the diaper thingy to happen? Like sickness? Maybe a potion gone wrong? Thatīs mostly how I play it...for my chara. I would be 11/ Slytherin student/ Snapeīs daughter.
As for being babied...requireing help in everyday situations, pacifiers can be included, mashed food, cribs...Thereīs a reason for everything...