I Think It Is Nice To Be Nice

I made a customer cry at work earlier, not intentionally of course. I'll admit I was tired, I'd missed school and I'm coming down with something, I'd already dealt with a totally swamped restaurant and a slew of rude customers. In short I've had better days. It's hard not to get impatient.
But this lady came through the drive-thru, it took her nearly 20mins. to order and I could hear her arguing with her kids through the speaker. When she finally got up to the window her total was a little over $25 and I felt bad when I saw her face drop and she kinda snuck a look at her kids in the back, I think there were two of them. And she asked me to take off one of the items she ordered. And I already knew from what it was she planned to only buy her kids meals and forget about her own. And I just closed the window on her, used my own card and added two extra burgers to the order, drew a smiley face on the back of her ticket and handed it to her. I told her it was free, that I was giving her a "pay it forward coupon".
And she got fussy and about it and tried to make me take her money though I don't think it was enough any way and finally she just leaned up and cupped my cheeks like my dad used to and she was all teary eyes and sniffling and her kids were confused and I was a little freaked out too lol and she just kept saying she'd pay me back and I just said no, I've been there.
My cook told me I was dumb for doing it but I don't care. Yeah I went on a limb, I'm a student, living at home with a crappy paying job and my own expenses and tbh I needed that money but oh well. She needed a good day too, everyone deserves a good day every once in a while.