I think that’s a bit extreme from the grandma. Toddlers are toddlers and they all have their moments. Just like adults some kids gel better than others. I tend to find my daughter gels best with children who are at a similar development level to her and finds those who are more developed challenging and those who are less frustrating - perhaps this is the case. It sounds like you’re doing a great job with her and she’s a great kid! Just keep going with what you’re doing and I’m sure she will grow out of this phase. I would try and speak to grandma too as keeping them apart isn’t going to help in the long term in my opinion. Xx
Definitely over reaction from grandma! - my boy is testing all the boundaries at the moment. Does she see her cousin regularly? Perhaps it’s because she enjoys the reactions she gets?
Maybe she feels like her cousin is a threat or competition to her or something 🤔