Getting young children to learn another language is a very sensitive process. You have to be very careful since the first impression is often the most significant thing that will be engraved in his/her mind. I have had many students who hated English before attending my classes, and I made them motivated - I made them enjoy what they were learning. You may want to knw why they didn't like English once? Simple. Because their first impression of learning English had beed very rough, incorrect, and irritating. I would absolutely be the same if I had been in their shoes. Children are very sensitive about this first impression!!!
Some linguists say that learning two languages at the same time is going to enforce a lot of pressure on children, and they grow up to be depressed by the pass of time - let alone other problems that may happen. This is not true at all if you help your child take a smooth introduction. Children like those rhymes, songs, vividly colorful educational pictures, and even certain cartoons on TV which are in English. You should help them enjoy what they like and also help them learn something - in this case basic English - in a fun way.
You may find this weird, but I personally watch cartoons with my little brother at times and start laughing at a certain scene out of the blue. My brother says:"What are you laughing at? come on, tell me what happened?! I like to know what happened that you're laughing?" and I exactly feel that the suspense encourages him to become motivated to learn English to enjoy what he watches even more!!!
Keep on doing what you are already doing, but do as you yourself are enjoying this too, or else your child will indirectly understand that he's got a naughty teacher at home and starts thinking like IS SHE MY MOM OR MY ENGLISH TEACHER?

It's ok to be both of course!!! and very enjoyable at times!
Ruholla Kazemi
EFL Teacher
EAP Teacher
English Teacher Trainer