As long as the dog gets exercise before and after being left she will just chill out. She will be fine. End of the day we do have lives to live and I can't think of anyone outside a small few on this board who would think crating a pup for 3/4 hours in the day to keep them safe is harmful. As long as she is trained to be relaxed when she is crated and have no collar or choke hazards and have fresh drinking water, and can stand up easily and move around change possition and sprawl out and stretch.. When she is older she will be fine to be loose in a room or the house and the more you get right when she is young the more easy it will be to leave her loose later on. Even loose in the house anything over 7/9 hours would be demanding for a dog to be left with no toilet area and then they can't be blamed for any accidents . With the crates it is the dogs who spend their whole lives shut in crates that most people worry about. But here some people are very anti crate and 3/4 hours is seen as cruel and night use is seen as cruel...it is the point at which useful becomes lazy or abusive people have different opinions.
My house is old and open plan and of the doors we do have none of them actually shut so crates are very practical and essential bits of equipment in my home for pups and now for my dogs at night (
which some people here think is torturing them.) and they are good for the car and for shows, to take on holiday etc.. I think they are very very useful .