Newbie.....dealing with a MLC'er....

[Amy40]

I just hate that we can't talk like adults about this. It always has to be on her terms.

Right up until YOU set the terms - and you can do that at this point because (1) you have legitimate questions about where and how she's living and (2) there is no custody/visitation order in place at this time (and lets not forget, she LEFT both of you).

Does your locality require mediation prior to the court hearing?

If so, that's where all your concerns should be laid out.
In my locality, a home study would be ordered.

If they don't do that (or anything equivalent) in your area, then you lay it down for the judge.
Your questions and concerns are legitimate.

Protect your son.
And let HER worry about proving that there is nothing to protect him from.