I'm glad I've seen this thread! My daughter (six months old next week) has had wonky eyes since birth, and hasn't grown out of it yet. Not sure whether she should have by now. Initially, I would have said her right eye turned inwards more than the left, but now it's most definitely her left eye that's most affected. Sometimes it's more pronounced than others, but I notice it all the time and in photos etc.
I had a squint as a child, requiring patches, and now as an adult I have fairly crap vision - high astigmatism, long sight. I was premature though, so I would be inclined to blame it on that rather than there being a hereditary aspect to it. My husband and all of his family, on the other hand, are all badly short sighted!
Mentioned it to the HV, expecting to be told it was nothing to worry about at her age, but said it was worth getting a referral considering family history. First GP I saw said I needed to take her to an optician, and if they believed there was a problem, she would refer. I was a bit dubious about this, and sure enough two high st opticians looked at me like I was bad when I asked if they could test a baby 
Took her to another GP who agreed there was "a lag" and would do a referral. Waiting to hear back now. So my question is, how common is this in a nearly six month old, and what the course of action would be if a problem is detected?