Welcome to our forum.
"My concern is that she is just going to keep dating/making love with different guys and that she won't find the 'one.'"
I suppose you could express that concern to her and get her thoughts on it, but ultimately it sounds like her own problem, something for her to figure out. Maybe she is just enjoying some newfound freedom right now and hasn't gotten down to the business of being choosy.
Just curious, are you having luck finding dates for yourself? Anyway, you are just getting started on this poly journey, so there will be a lot of stuff to figure out along the way. Take advantage of Polyamory.com and read various of our threads according to what calls to you. Post your thoughts and questions along the way. We have a lot of collective wisdom to share on this site.
Glad to have you aboard.