Given that you are going to have her assessed and properly diagnosed - which would be necessary anyway, before any medication could be given - then I recognise that you are aware that there are procedures which need to be followed, etc.
Four is young, but in my opinion not TOO young for medication, if it is considered to be advisable. It really does depend on the child, on the circumstances, how the child presents, what has already been tried - so many things.
difficult child 1 was clearly having problems from very young, but I kept getting told (by the GP and the district nurse) that nothing was wrong. As a result he was 6 before he was finally seen by a specialist. That doctor required us to jump through some hoops before he would prescribe medications. First we had to see if diet made a difference. It didn't, but it was a worthwhile exercise for us. I also put myself on the low-allergy diet, to see if it made a difference to me and also so difficult child 1 wouldn't feel singled out. We DID find that two things aggravated his behaviour problems - caffeine, and oranges.
With difficult child 1, once we had demonstrated that there really weren't any alternatives, the specialist prescribed ritalin (Concerta was not available in Australia at that time). We found it brought amazing improvement, but it was not anywhere near a compete fix. However, we were grateful for any change for the better. We did find also, that caffeine would undo the benefit of the medications; difficult child 1 was at a party at school and drank several glasses of cola, which was enough to negate the benefit of the ritalin.
As time went on, we realised we couldn't give difficult child 1 a holiday from his medications (as was often suggested at the time) because he had difficulties coping with the confusion of whether medications were on board or not. With medications on board, he knew what he could do. Unmedicated it was much more difficult for him, but it was still something he could cope with if he was aware of it and stable. But when he was used to being medicated and on an even keel then we let medications wear off and he had to change what he was used to - then it was the most difficult for him. We also discovered later on that he had problems with rebound - as medications wore off, it was as if all the symptoms that had been kept at bay for the day, all surfaced at once. The pendulum would swing much further back the other way.
We changed specialists (many reasons) and difficult child 1's medications were doubled. This greatly improved his performance in class but it also greatly increased the rebound problems.
Then we became aware that difficult child 1 was not an isolated case in the family. Because we needed a specialist who could manage all three of our problem children, we had to change doctors again. This doctor changed difficult child 1 to a new medication - dexamphetamine. No rebound problems. We talked to friends with similar problems and found that rebound could have happened with either medication. This same doctor diagnosed difficult child 3 as on the autism spectrum, revised difficult child 1's diagnosis to Asperger's Syndrome and also diagnosed easy child 2/difficult child 2 as having some Asperger's traits. All three were diagnosed as ADHD as well. Oh, joy...
difficult child 3 was by this stage three and a half years old. He was non-verbal, apart from some simple words which he could read. He had a good understanding of phonics and could read text aloud but had limited understanding. HIs vocabulary consisted of maybe 20 nouns which he knew and understood, and the entire script of half a dozen movies and most songs on the pop charts. However, he seemed to repeat the words as if he was remembering a very long sequence of sounds, rather than anything with any meaning.
difficult child 1 was started on dex at 3 and a half. The difference in him was remarkable. Again, no way a cure, but it was enough to make it much easier for him to make the next leap in his language development. In so many ways, his ability to pay attention more consistently to the world around him opened up so much more opportunity to him.
We copped a lot of flak from family, from friends, from relatives, for medicating him so young. But we had the confidence to keep on with our decision because the benefits were so apparent. Even since then, when well-meaning idiots say things like, "What do you think about those irresponsible parents who drug their children into submission?" I still have confidence to tell them, politely, just how narrow-minded they are.
But you DO need to be prepared for these people. They will tell you, so you will need to feel sufficiently confident that medicating your child is the best decision.
IIN order to ensure it IS the best decision, you should cover all bases and also ensure she has been thoroughly, carefully, comprehensively assessed. You also need to look into all treatment/management/support options.
Marg