Seamstress Saturday - A side job

Every now and then, I get a request to do some repairs or alterations of an item from someone in the neighborhood.  Most of them are quick and easy type of sewing but they are very appreciative of the quick turn around of their item.  And of course they offer to pay whatever is the going rate of my work.  But of course there is always an exception to the rule.  One of them had asked if I can help her fix a dress and what I understood was that I would show her how to do it and she will continue.  It was my mistake maybe, I misunderstood, she just want me to fix it.  In our conversation, there was no offer to pay and I didn't really want to ask in the hopes that she will offer to pay once the job was done.  It took me a few hours to repair the dress as it involves both machine sewing and hand sewing.  When all is said and done, I delivered to their home and I got a thank you.  No offer of payment or maybe a $5 Tim Horton's card. LOL.  Just to compare with other neighbors, they would ask how much and most of the time they would pay more because I am giving them a good rate but they know that the job takes a lot of time.  Or if I didn't mention an amount, they would just get me a Tim Hortons gift card because they know I love Tim's.  A few months later, the same person ask to repair another item of clothing. I was not sure how to respond because again, there was no mention of the offer of payment.  For one reason or another I felt bad refusing but it was uncomfortable situation.  It felt like I was one of her servants and that she needed help again.  So I replied that maybe she should take it to the cleaners as they have seamstress there also.  She said, she already asked and they were going to charge her $60 for the repair, and that is the reason why she is asking for my help.  Truly, I don't mind helping people and don't have to get paid, but for whatever reason it's all about the way you are treated.  I would like to think that I am a generous person when it comes to my time.  What would you do if you were in my position?