My question involves collection proceedings in the State of: Iowa

First and foremost, from what I've briefly looked into, the limit of statute in my state of Iowa for oral agreements is five years. This has been the most consistent figure I've come across, although one did show two years. Either way, I feel my case is still eligible for a hearing. I'll start by giving a general description of what's going on.
I leant my girlfriend (ex now, imagine that) a somewhat large sum of money ($5,000) in order for her to purchase a vehicle a little over a year ago. We had the agreement that she would either get a loan and pay me back, or just make payments over the course of a few years. Stupid on my part? Yes, however I felt bad as she has no mother/father or any family living and is putting herself through school. I was quite certain she would pay me back as well, as she was always very trustworthy, far more so than many other people I know.
What I have going for me:
-A text message saved (from her number i.e.: ***-***-**** and not her name so it can't be argued that I had someone else fabricate the conversation then change their number to her name before taking the screenshot) which states that she aknwoledges she owes me money, and states that she will be getting me a loan. Although this does not disclose the amount of the loan, it's better than nothing. I also have a brief Facebook conversation also dealing with the matter but never the specifics.
-I can go back through my bank statements to the date and see that $5,000 withdrawal. Although it's not 100% proof that I lent her that full amount, the money never went immediately back in, nor later down the road so it was obvious it was spent on something in that short duration after its withdrawal.
-I know the dealer who sold her the vehicle, and he witnessed me sign the check that day, and I believe I also signed one of the papers for him there. Not sure how useful this is.
-Shortly after we went our seperate ways, she and a couple of friends apparently were apprehended for shoplifting, and convicted although on what counts I am not sure. I on the other hand, have a squeaky clean record. I'm also not sure if this is of any significance but I figured I'd lay it out on the table to see what we're dealing with.
What I have against me:
-Obviously I have no legal document stating any sort of disclosed amount or time frame in which she needs to pay me back. I'm not sure if that means I should just give up or not. I have bills of my own to pay and I could use this money.

My best friend from way back has a mother here in town who is one of the more prominent attorneys in the area. Before I went to consult with her, I wanted to see what my chances might even be. I understand people make these sorts of agreements all of the time, but my question is whether or not the loaner ever actually wins.
Thank you.