both my dad and my wife's mom and mentally it has taken its toll on her.
We got her into a few therapy sessions that have helped her a little to give her a place to process her emotions. Make sure you get a therapist that doesn't want to make it a permanent thing.
However, like our therapist said, it's super important to understand that at this stage almost all cases of depression are temporary. My daughter has gone from blaming her sadness on her depression to no longer feeling sadness all the time but being able to process it and find positive and healthy outlets.
Finding the things that make her happy has been very beneficial to helping her deal with this and she's almost out of the woods with it. Find the things that make her don't feel depressed (for my daughter it was theater and basketball). Something that we've been careful about as parents is making sure that her friends are people that do not help exacerbate the problem. Friends are the biggest influence at this age other than parents so make sure she is spending time with people that uplift her and not bring her down.