[she talked about not wanting to be alive]
That is yet another clear sign it’s a mental illness.
If one states some suicidal feelings at age seven....the odds are that they will still be suicidal at age 20...age 30...age 40, and so on. You can gender-up or medicate yourself to whatever extent you desire....you have a mental illness that will be a life-long situation.
You are right. He might be all smiles now twirling in his dress while his mom beams her approval, but what will happen when he becomes a teen? He can wear makeup and twirl all he wants in his pretty pink dresses, but when the boys are reluctant to date him will he turn suisidal again?