That's pretty low on her part. I'd have asked her which bags are the kids clothes and only take those. If she can't take the time to do something as simple as laundry, she probably has many more issues you're not aware of. If this starts to get out of hand and she gets worse, you should really consider going for full custody. Something tells me you'd win that battle in court very easily.
I have had lawyers tell me I've got a "good" chance but here in NC the woman basically has to be complete garbage to lose her children. Now if I find out they are in poor living conditions I'll get SS involved and take my kids the easy way. If her living is unfit then I'll get custody automatically as long as my abode is in order which its pretty much spotless atm and has been since she left.
Turn, Reading over this again just made me realize how similar our situations are with ex's. The little things that happen that are small little power struggles as the ex refuses to believe you would actually leave and tries to treat you like you haven't in hopes of getting you to come back. Indiana court system is very similar and its easy to feel defeated, but trying to get custody is a marathon...a lot of people try to treat it like a sprint and get fed up immediately. Just keep your head up and keep trying no matter what.