Birthday Question

Hello! I had a question I was hoping to get some advice on. Im a regular babysitter/nanny (I watch the kids almost every day, I just use the title babysitter) to 4 kids, 3 girls and 1 boy. The boy turned 3 in June, the oldest girl turned 11 in July, and the youngest is turning 2 in August. The three kids are having a combined birthday party close to the youngest's birthday.

My question is: I already gave the oldest and the boy their presents after their birthdays past. Im wondering if I should get them anything for the birthday party? If I did, it would be a smaller gift than what I got them for their actual birthday. I was thinking, if I should get them something, get them an outfit and maybe a book or a small toy. What do you think? Also what are some good present ideas for a 2 year old? Thanks!