Evicting Sil Legally

Location: Indiana, Marion County specifically if that matters

My SIL has been staying with my wife, myself and our kids since last July. She had gotten out of rehab and needed a place to stay. She was clean then. We did not place her on a written lease at the time, given she was indigent and my wife did not think she would be with us long. We have an unfinished basement she sleeps in and we never imagined anyone would want to stay there very long anyway.

She has been working and will occasionally give my wife $40 - $50 books every few months, but we have never asked for money from her verbally or in writing. We wanted her to save money so she can move on.

While we were away last Thanksgiving, she allowed her homeless ex-husband to come over and use our shower. This was an absolute no-no, given his drug history they should be having no contact and we had specifically told her he was not to be on our property under any circumstances. I did not find out this had happened for several months, and she managed to convince my wife to not tell me. This of course didn’t play well with me when I found out, but my wife has accepted she was wrong and told her sister there were no more chances, period.

Well, last weekend we took the kids on vacation. Our pet sitter noticed that my vehicle was gone when she came to feed our cats. She took care of them then texted us after she left. She’d also talked to our neighbor, who reported my SIL had been sitting in the back deck with a man fitting her ex-husband’s description.

I tried to file a police report but could not as we are out of state. I was told be the operator that our pet sitter may be able to do so if she were at our property. So she went back, and at that point the car was back, so she didn’t stop.

My wife texted her sister just kind of fished and played dumb, asking how things were, and she was told they’re going great, and was asked when we were returning. My wife told her it would be this weekend, unless we needed to hurry back to file a police report for a stolen vehicle. My SIL tried to feign ignorance but quickly gave up and said she’d used my vehicle to get her phone, which she’d left at work. She also immediately admitted she’d let her ex sit on the back deck with her, but had not allowed him in the house. Sure…

My SIL did not have permission to use my vehicle. She has no license or insurance, and we have in fact refused her a couple of times when she’s asked permission to use it. I’ve explained to her why she can’t use it, in great detail.

As of when she brought her ex over, he was wanted in our county on felony shoplifting charges and was on bail for felony drug charges in another county.

So now we’re on our way back home. Our cat sitter is now just house sitting to make sure nothing else happens. My SIL apparently doesn’t grasp the severity of the situation and that we’re going to evict her post haste.

My understanding is that in this situation, the SIL is basically a month-to-month tenant and I can give her notice as such. But does that mean 30 days, or evicting her now will mean she has until the end of July?

Also, given that my SIL used my vehicle without permission (and in effect used my vehicle to commit a crime by driving illegally), she used our home to give aid to someone wanted on felony charges and helped him trespass into the property, are there legal avenues I can use to expedite eviction? I do plan to file a police report.

While I will say thank you in advance for all legal advice, we already know we fucked up letting her stay in our home without a formal lease, and we should have kicked her out already. Pointing out where we messed up isn’t going to help anyone now.