My dentist allowed me to make payments on a $1689 bill for root canal/crown. It took a year to pay off. Its best to ask if they will let you do that first though.
Asking if they accept installment payments is a good idea, but in this case, it appears the bill was only $50, half of which she was paying now and the rest a week later. I can't imagine a dentist not accepting that although they could, I suppose, add a late payment charge.
No, it's wise to do it for lots of reasons. It will likely keep you in good standing with them, stop them from taking further actions, and will help you whittle down the bill. Most places are glad to work with you on payments.
There's a chance they may even write a portion off if they know you're experiencing hardship. There are no guarantees, but it's always worth mentioning to them.