Can you give her an option? Eg. You can either sit in the stroller or hold my hand. If she doesn't want to hold your hand then in she goes.. For overseas can you take a sling/carrier with you instead?
With the high chair maybe she just wants to feel more independent. Is she old enough to sit on a booster seat on a big chair? We have a fisher price booster seat with adjustable height and it has been fantastic. You can also get cloth seats, that are really just to help them to not fall off the chair that you could take with you?
Toddlers are all about being independent and pushing boundaries