Jiggity Jig

Oh boy. I have not been feeling "great" the last few days. I decided this is probably a UTI. Tried the home remedies, then some commercial ones. With a trip on the horizon, I couldn't face a 13+ hour drive feeling like this.
So, $130.+ in Doc fees plus $20+ in antibiotics... I am waiting to feel better.

I have, as I said, not been feeling great. But grand daughter and I went to the library yesterday (Tuesday) none-the-less. Summer reading program. Afterward, I got her an ice cream cone at Sonic. (Didn't think to ask about what the Library SRP snack had been.)
Once home, I had *intended* to have grilled burgers for supper. But at the time to start the grill, we had some severe weather come through. Mr C called about then, so I asked him to bring home something else for supper. He did. We had fried chicken, and some "Becky's Green Beans".
Nickole gobbled up a chicken strip, and asked for more. I said Yes, as soon as she finished her green beans. (She had about 6). Half an hour later, I set the dreadful TIMER... finish your food in ___ (20) minutes or get MORE of what you're trying to avoid eating. (I felt 20 minutes was completely reasonable to eat 6 green beans.)
Green beans were eaten in the time limit, and seconds on chicken were ALLOWED (not forced). Three bites in, and she wanted to be done. I was unreasonable. Nope... if you want seconds, you should eat them and not waste them. (Or not take them at all, as I had pointed out when she wanted more). She finished the chicken. But then, the dilemma.
She wanted ice cream for dessert. I said, "Later" as she was obviously full. (She'd taken the better part of an hour on six green beans and two chicken strips). About 25 minutes later, she came and again asked for ice cream.
I was agreeable.  Since she'd already had a cone earlier, and had been reluctant to eat supper... I gave her a small amount of ice cream. Adequate for a taste of dessert- not stingy. She GLARED at me, and asked "What's THIS?" in her imperious tone. She told me she should get "at LEAST two scoops- one for every hour she had to wait after supper before I gave her ice cream!"
This did NOT set well with CowGranny. I snatched back her bowl of ice cream, and the dog had a nice treat.
Mr. C felt I was mean and unreasonable. He was outside during the high decibel screeching and raving that went on.  Since Mr C thought I was unfair, I have been questioning myself and my motives. I know I would of reacted the same way had any of my kids or other grands behaved like that... and maybe added immediate bedtime or a spanking. Mr C says I ought to have handled it differently. I ask you... what should I have done? I don't want to cater to a sense of entitlement. I'm not asking her to bow down and beg for every morsel she gets. Where is the course of action?