Therapy for child

I’m wondering if therapy should happen in this situation. Backstory- my niece is 8 and she’s been through so much. Her parents were together until she was about 3. So those first 3 years, she witnessed a lot. Them fighting, having sex in front of her, they both did drugs and her mom once told me that my niece handed her a pill she had found on the ground. Thank God she didn’t eat it. But you get the gist of the situation. So then her parents separate. Her dad meets a new woman and has two kids with her. This woman (the step mom) is very mean to my niece and resents the fact that her husband has this child with another woman. She treated my niece like garbage and would do things like- if my niece and her dad went out to the store and he bought her a doll, her step mom would take the doll and hide it and then return it so she could buy something for her own kids. If my niece tried to sit by her dad to watch a movie, the step mother would literally shove her out of the way so SHE could sit by him to watch the movie. So that’s her dads new family. And to this day my niece says to me that she knows her step mom “hates her”. Then her mom moves in with a new guy and they eventually have a kid together. My niece lives with them pretty much full time other than when she went to see her dad, but that got less and less because of how his wife treated my niece and he couldn’t care less anyway so she didn’t have that good father figure. So eventually her mom and new boyfriend fought a lot, he apparently abused her etc. then they find out my nieces mother and father were secretly meeting up again and lots of drugs involved etc and my niece even pointed out to the family where “mommy’s stash” was and sure enough she was right. so now her mom is gone in rehab and her dad is just doing his thing. She’s living with her grandparents, my in laws, and I have her for virtual schooling everyday. She’s in great hands now. She is a good kid, but personally I think she should start therapy to discuss everything because I don’t think she’ll ever be with her mom or dad again. My in laws are trying for custody. Even though she seems pretty normal still, I’m worried it could turn into problems in the future. But no one really agrees with me because she’s not a trouble making kid. And they think it’ll be a waste of time because my niece is very very shy and doesn’t open up to people unless she REALLY trusts them. Like she won’t say a word or answer people if they ask her questions unless she really really knows them well, and she also gets super defensive if anytime says anything negative about her mom, understandably. So they dont think she will open up to a therapist. but child psychologists are trained for this. anyway, my point in this is to see what outsiders think- should she start therapy even tho she hasnt "acted out" or had an "episode" yet? it cant hurt, right? thanks in advance