The daughter lost a parent. Losing an intimate social contact at such an age is devastating. True, most would've been able to process their grief well, cope with the loss, and move on. Unfortunately, most does not mean all. Some are unable to, and the daughter is an example. Because of her mental and emotional situation, she is unfeeling of the emotions of others and the help they provide or wish to provide, sometimes taking for granted what is provided. Only after others withdraw from her as well will she either realize their efforts or realize further abandonment.
The father lost a wife. He is overworked. His daughter is unwell. He feels unappreciated. True, he works hard to care for his daughter and succeed in his work. This is how he decided to cope with the initial loss. However, his 'focus' does not compensate for what is actually needed for him to do. Supporting family economically does not equate to supporting them emotionally. He also decided to raise her daughter alone despite offered help from relatives, partly ego and also partly because it is his way of keeping control of his circumstance. His inability to adequately cope makes him do things he would otherwise not do, and seek approval from those who would willingly give it with little regard for the ramifications.
The friend seems to have domestic problems as well. Having a strict family with a domineering or controlling parental figure may have led her to become rebellious and seek behaviors where she is in control. Having parents who constantly surveil you can lead to a loss of sense of privacy, which is important at this age, and pushes her to keep secrets instead. Again, most would be able to work through this healthily, but most does not mean all. Her 'attraction' to the father may have underlying causes, but I don't know at this point.
TL;DR They all deserve certain amounts of sympathy and understanding. The amount you can afford depends on the biases one inherently has for people with the characters' circumstances and one's ability to have an impartial perspective. There are better options to deal with things, true, but alas, humans don't exactly choose the better option every single time. For the characters, they chose not ideally.