Shared custody

Hi. I have a shared custody arrangement with my ex-wife. It’s unequal in terms of our time with the children - in her favour - but I’ve lived with it for a few years in the interests of maintaining harmony around the children. However, she is now spending more time away from home, to yundertake a training course 150 miles away. Where her absence is in the time during which she would normally have the kids, she is asking her parents to look after the children (rather than me). She says it is her choice to do that given it’s during “her time”. As the other person with parental responsibility, I feel like I should be given the option to have the kids when she is unable to look after them, rather than they be sent to her grandparents. I feel as if I should be given priority over her grandparents given how disempowering this arrangement is for me. The kids (both under 10) would also rather come to me. Anyone with any similar experience to share, please? Thanks.

Wow, our circumstances are very similar. I'm still going through the divorce process and have only one child aged 11. I've remained in the family home less than a mile from his school and she keeps him the majority of the week 4 miles away with her parents and sends/collects him to school with various relatives, thus denying me the right to parent my own son.
She works as a teacher and has to be in class early, I however work from home, the family home she walked away from.

She's steadfastly refused to budge or negotiate, looks like family court now. Again great question and I look forward to many more contributions.