It sounds like she may be herdbound. If she is very dominant in her pasture, a horse can get uncomfortable when they are not in charge and do not want to be told what to do. Maybe see if you can get her into a different pasture away from those she is getting too close to, and lots of ground work and lunging to make her respect and listen. If she is calling out for her friends, make her work.
She also whinnies really loudly when I'm on board. She's not bucked or reared with me, only others helping me and doesn't do it to everyone!? She is super forward st the mo too whereas I used to ride with a stick!?
Thank you. Her tack was only fitted 3 mo this ago, defo not this although she has put on weight. She's napping, rearing when being asked to work work. There are certain traits she is getting away with on the ground with me but not much. She is bossing a 25 year old boy pony around now ... could her dominance be coming through this?!
Make sure you are stern with her on the ground first. If you or someone else is letting her get away with bad behaviour when handling it may translate to riding. Also check with your vet for any pain that could cause it