Is my dalmation mollie lonley?

It would be best if she was kept in a group of her own kind. Mollies aren't schooling fish, but livebearers such as guppies, swordtails, endlers and platies thrive when kept in groups of three or not. It's up to you if you want to keep her or not, I ume that she would be fine with the guppies and tetras, but if she starts becoming skittish and stressed, I recommend donating her to your local fish store.