W wants me to sell the house....advice please

[native]

W has a close friendship with a very depressed, sometimes suicidal girl whose lesbian partner committed suicide about 10 mos. ago.

This girl has grown very attached to my W and has made overtures to her, bought her clothes, bought my d6 clothes, and spent more one-on-one time with W in the past 10mos that I have.

Before W announced she wanted a 'trial seperation' she spent huge blocks of time with this girl. At first I thought we as a couple might be able to help her through this hard time, but essentially this girl became my W's project and took her away from a family she was already poorly connected to.

B4 this girl, it was another friend who took all W's free time.

W has always been compassionate to needy people, but it put a strain on our already strained R.

Eventually W got tired of me trying to control her 'free time' spent with Project Girl. (any time after work was considered her free time. No duties to taking care of child, cleaning, paying bills, anything) and this seemed to lead directly into the announcement that she wanted a seperation and accusations of me trying to control her.

From my point of view however W had abandoned me and D6 to spend all her time with this 'project girl' (who is a relational vampire and a spiritual 'dark hole' as far as I'm concerned).

We are now 7 mos. past the bomb and 1 1/2 mos. into physical seperation, and W continues to see this girl, even after her mom, who is about as open as one can get to diversity and odd birds has told her that she doesn't want 'project girl' around her house, that she feels this girl is dangerous and could hurt someone. (Anyone can see this girl is seriously odd, which isn't to condemn her, but how is her company helping my depressed W get any better?)

"Project Girl" continues to buy clothes for W. ( I asked her why PG buys her clothes. W says PG just likes to.) I also noticed a new shirt on my D. that PG bought.

PG is a trust fund baby who has a menial job but lots of available funds to buy stuff, which I cannot since we have put ourselves into so much debt and my livelyhood has been diminished

Both I and W's mom have asked if W is 'attracted' to PG, but she denies it and I believe her. (I think having someone more screwed up than herself makes her feel better, plus she's 'helping' PG). W has admitted that PG has expressed a romantic interest in W. Obvious, since she is using her trust fund $ to try to buy my W's love.

My Dilemma:

I don't want PG buying clothes for my D or have anything to do with D. I feel threatened by the clear and obvious attempt to woo my W.

W is not lesbian, but I still do not want this person having anything to do with D6. PG is emotionally unhealthy and clearly not supportive of our marriage.

W may not respect my concern, but I have rights as a parent too.

Question Anyone:

Do I approach W with an ultimatum (no contact or clothes buying for D6) or request, or do I need to see an attorney, since at this point we are seperated (have not signed seperation papers yet)and headed for divorce according to W a few days ago?