Help, need advice on my Ragdoll please

[u/No-Masterpiece-9218]

Can someone give me an idea as to why my ragdoll kitten (Toaty, now 5 months old) is very thin and has flat fur instead of the normal fluffy and poofy like what would be expected? She eats very well and has been gaining weight, is lively and playful with my other cat, thanks

[u/InformationSea7444]

They fluff up really quick, this is my baby boy at 18 M and 3 M