Should I have both my puppies spayed/neutered at the same time? I worry that the smaller one will be ok?

Get it over with at the same time, the males need very little attention after the procedure and the female will be very sore for the 1st day by the 3rd she will be back to normal. It is easier to play nurse to them both at the same time and if the male is less hyper then the female will be less likely to pop her stitches. The female will always take a little longer to recover probably ...just keep and eye on her but you should have no problems, the vet will advise on keeping stitches clean ect... good luck!