just my 2 cents, but since you mention that English isn't her first language, you could also be dealing with some cultural ideals of what is appropriate for a child of this age. I agree, you need to make it clear what you expect her to do FOR your son, not TO your son.
FWIW-I also really feel for him with the communication/babbling. I seem to have a knack for deciphering early speaking and have been able to clearly understand DD4.5 since she was only about 20 months. With DD8, starting around 10 mo, she would push things away (like a spoon when she was finished eating) and say what sounded like "monkey shoes". She was well past two when her ability to make her mouth move properly caught up and we realized she had been saying "no thank you" all that time.
DD4.5 has totally been dressing herself since around 2 and I do the same thing, always talking to my chldren, giving the explanations before they can ask, I guess, so they are used to having things said before they even get frustrated.
