so could it be her age
It could be when she was newborn, with the physical smallness of her mouth and jaw muscles. There are lots of reasons though, it might not be this.
My youngest was anti anything that wasn't a nipple. She was EBF and was refusing dummy and also bottles of expressed milk. I just persevered. As soon as one was sorted so was the other, so they must have been linked.
How did you find it when the time came to weaning them off their dummies?
No hassle at all. I do have realistic expectations though. I know children need comfort in order to sleep right through until school age. So I was in no stressful rush about it.
I went with free dummy use for the first 6 months - when mostly life is about sleeping anyway. From 6-12m reduced use to just sleep times. By 12m the only dummy we have is attached by ribbon to the sleeping bag. So the only place she has the dummy is in the cot when sleeping.
By 2y she uses the dummy for 10 mins or after going to bed, to drop off to sleep, and that's it. So 20 mins at most per day (bedtime and naptime) is not harmful to her teeth, but continues to give adequate comfort to sleep independently and alone.
Aged around 3-4 I've offered a special present for when child can do a week without the dummy. Made it the child's decision to stop, not mine. When child ready to earn the present, dummy goes. No stress. No tears. No hassle.
Mine is a whole different ball game to the type of parent that gives their toddler a dummy all the time. No one ever sees my daughter with a dummy and havent since she was 1.