What should I do?

Hi, my neighbour hired me to cut her gr every week for $20 a cutt. I had done it for the past 8 weeks without no complaints. I did it twice in the past two weeks and she is yet to pay me. When my dad asked she said it wasnt cut properly, and that there is still uncut gr around. When me and my mom went to look the only uncut area was by the curb and I could't do that without a trimmer. She hasnt paid me back, my mom though told her we want the money. She has joked around about sending this case to Judge Judy and has even taken some pictures. But they really do feel that I should get the money for the two times I cut it? So what should I do? Thanks