Is it normal for a 10 week old kitten to suckle a 7 month old kitten?
Yes this is normal, but its not healthy for your other cat. the kitten could actually really hurt the 7 month old cat since she isn’t producing milk, but I guess just watch for redness and sores since separating them might not be necessary at this point. The 10 week old is still in the process of weaning from mom, but has been abruptly stopped too early. 10 weeks is ok, but 12 weeks is ideal. Cats who are not properly weaned can grow up with lifelong issues like suckling on things including cats, blankets, fingers, etc. And I would recommend getting your other cat fixed ASAP too because you don’t want raging hormones with a baby kitten around. It could be an unfriendly combination.