The ‘iddah following divorce (talaaq) must be one of two things:
1. Either ‘iddah following a revocable divorce
2. Or ‘iddah following an irrevocable divorce.
If a woman is in ‘iddah following a revocable divorce, it is not permissible for her to go out except with her husband’s permission. But if she is in ‘iddah following an irrevocable divorce, then she may go out if she needs to, even if that is without permission, because she is no longer a wife.
It was narrated from Ibn ‘Umar (may Allah be pleased with him) that he used to say: If a woman has been divorced, then she may come to the mosque and it is her right to do so, but she should not stay overnight anywhere except in her house, until her ‘iddah has ended.
If one can go out and it would involve interaction then it stands to reason that going on the forum would be the same thing. I would check with an alim but i'm guessing he would say the same thing.