Disability or some sort?

GirlMom💗 • 2015 👧🏼 2017 👼🏼👼🏼 2018 👶🏻🌈
I do home daycare, I have a LO that will be 4 in April. Can't take shoes off, put shoes on, doesn't know how to put clothes on. Is really sensitive to the way someone talks to them. LO is a twin who was born last (not sure if that means anything). They're a lot slower than the other twin and compared to my other kids around the same age. They will sit and stair in a daze at times. You repeatidly have to tell them to do whatever it is they're doing. The parents have tested them for autism but that wasn't the issue. I haven't brought it up to the parents because I know they're aware, but it's a sensitive subject as well. Any idea on what the matter could be of what I could do to help or say to the parents. I also don't want to point fingers like thinking its a disability, but something more than a learning disability is wrong. The actions are just odd and unsual compared to anyone else.