Yes, I think you should see a counsellor with her.
Start with GP and have things like vitamins and mineral levels (iron, vitamin D etc) and thyroid function checked, to see if there is something like this causing depression. The aches and pains are real, not made up, she's probably embarassed about telling you, needs to get it checked out with a doctor.
Has she ever given any indication that she turns her feelings inwards, such as self harm or suicide? She will need to be open about this with a doctor and with counsellors and if it upsets you too much, she might clam up.
I'm not qualified or a medical professional, have a DD with MH problems and all the kinds of behaviour you talk of was my biggest concern, but DD hid everything and lied about how she felt. (Long story).
She's still not well, but is on anti-depressants which means she is able to feel more positive about family most of the time . Our relationships with her are much improved, her school grades picked up and she now has a social life and is aiming to learn how to manage her illness and life's checks and balances ready for Uni/leaving home/work. She still has 'flat' moods and some background suicidal thoughts or images, and other symptoms. Counselling isn't a cure, it's a resource to develop better ways to manage life's difficulties. Anti-depressants help her (she hasn't been violent since being on ADs) but she can't feel/see it herself.
The other thing I would stress is, build some weekly 1-2-1 time with each of your other family members, as a mental illness in the family can become all encompassing for some parents (especially when your DH isn't able to deal with it).