I was also wondering how you could see if someone had a happy or traumatic childhood. Taking my 4th you would think, mmm..... Uranus. Like I said, connection with siblings minimal and this is also shown by my 3rd house, ruler Saturn who squares my Mercury absolutely exactly. I think we should always look at houses 3 and 4 in connection with one another as siblings belong to your family.
Traditionally Aquarius is also ruled by Saturn, so in my case makes even more sense to combine both.
Going a bit further, Saturn is in Leo, ruled by a very diblitated Sun in the 6th, in Taurus (shows maybe that my parents also stayed together until they died) but opposes Moon in 12 (showing tension between my parents which I only found out about when my father died and I found letters)and squares modern Asc. ruler Pluto. Lovely T-square in other words.
From this you would probably think that I had a difficult childhood and I probably had, but, and now comes the big "but", I can only remember being very happy as a child (except in school where I was pestered, but I never made a point about that, happy with just one boy and one girlfriend I had,) but in the family always felt happy, good relationship with both parents, never fights. I had a very good life, dad with good position, great houses, never financial trouble in the family, great vacations, you name it.
So am I denying unhappiness with that Moon in the 12th in Scorpio? (really badly aspected!)
Is my Jupiter conjunct the Ascendant maybe making me see things always from an optimistic side? Why is it that I can hardly ever feel realy close to someone even though I like them very much? I once had a much older cousin who told me she always felt so sorry for me and I was astonished when she said that. I never felt like a "poor me".
It has always, as psychological astrologer, fascinated me to figure out that 4th house (together with 3 and 12). Actually, the first quadrant of a chart reveals, I think, most of a persons character.