Is it normal for me to become closer to another family other than mine?

Sometimes it is easier to be close with complete strangers - there is safety in the newness (or temporaryness) of the relationship. Also, I wonder if there is any bias - such that you see your own internal family dynamic as complicated, messy, and problematic, and you see their family as whole, positive, perfect. If you ask someone in that family about their experience of their internal dynamic they will probably feel the same about theirs as you do about yours. This is a thing we do with viewing others and viewing ourselves (as individuals and as groups). So know that it is totally normal on all accounts.

Yes. Often times people tend to grow apart from their family emotionally, especially if they feet up in a strict or religious house hold because they feel like other families are less judgmental. All though that is not always the case. Some times people just tend to vibe a little better with people that they feel are not being “forced” to stay in their life. There was a time in my life that I was asking my self the same question trying to figure out if I was disappointing my family or my self in any way. However, it is completely normal.

It is not abnormal. If your family treats you a certain way and you don't like it (calling you names, belittling you, choosing siblings over you, etc.) and this other family does not do that to you, it is a totally normal reaction for you to mentally and emotionally become closer to this family. This family treats you how you would like to be treated, your family does not. Your brain will begin to see this other family as healthier and will essentially, see them as your family. Do not worry about it, you're likely experiencing a totally normal response to disliking your own family.