We start learning our mother tongue from the moment we are born. In bilingual families, it is more natural for a mother to speak to her child in English and a father in Hungarian - both in their own mother tongues. Does it occur to them that it is too early to speak to the child in their mother tongue? Will the child learn to speak both languages? Of course!!!!
The Helen Doron method builds on the natural ability of a young child to learn any language - even several languages in parallel - effortlessly and at a native-like level by the age of 6. Because the Helen Doron method is a mother tongue method, the earlier your child starts learning English, the more he or she will feel it as a second mother tongue! It's a skill that only lasts for a few years, so use it while you can!