Legal rights for a private day home

I have a private day home in Alberta and I am having a very hard time getting payment from one of my moms. She is a single mom of two girls and her fees have gotten very high (almost $900). I allowed myself to be emotionally connected to her hardships and allowed her children to continue coming even after several verbal payment promises were broken. At the start of the month I told her that her children were not allowed to come until her fees were paid. She did make arrangements to have her fees paid this past Friday but she did not come to my house, call me,text me or make any arrangements. Now I cannot get a hold of her and she will not return my messages, e-mails or phone calls. What can I do to get the money that is owed to me?

I would just let her know that if you don't receive fees by end of day tomorrow you will put her account in collections. then you don't have to have legal fees or even deal with her again, the collection agency will. They take % of the money owed.