In my case, I trust my parents, so it's not an issue for me to share personal details about my finances with them, just like they share everything with me. But that is my case, therefore I can't say every parents are going to be trustworthy and loyal to their children, because there are situations where parents took advantage of their children and even commited crimes against them, while the opposite has also happened in other situations.
Cases of parents taking advantage of their children or vice versa are rare and we should be flexible if we are unfortunate enough to find ourselves in such a situation. Also, most parents are the most trustworthy people in this world because without them there would be no us, without their upbringing we would not be here today. So if we doubt our parents, then no one in this world will trust us, let alone give us the right to doubt others.
If the situation dictates it - then the parents, your own blood, cannot be trusted. There are different cases, but naturally, everybody would expect warmth and security from your relatives to you and vice versa. However, sometimes, it's not the case, and many just crave this because they didn't feel it in the first place. They crave the ability to trust somebody like a family member to them.