Rachel is a girl who has lived rough. She will have previously used violence to defend herself and her pack. Moreover, she has been extremely conscious of the need for contingency planning (typically expressed in terms of bug-out bag preparedness). She is in excellent physical shape due to woman-handling animals, large bags of feed, etc.
Also, it's a farm. It's her farm. There all all kinds of outbuildings, there are odds and ends all over the place in ways that create hazards if you don't know the space, there is lots of stuff to use as improvised weapons, it's dark with no natural light, she knows the terrain and the attackers don't, and the attackers rarely if ever do ops outside of an urban environment.
Rachel has also been training with the PRT K-9 trainees, and doesn't give a shit about how scary the Empire is supposed to be.
The Empire has shit tactics here. They didn't plan the op, they didn't scout and they didn't rehearse. They keep splitting up, and didn't even register that their comms would be fucked up by their own jammer. This is particularly bad as in this scenario, risk of friendly fire is especially high for various reasons. This means the attackers are more likely to hesitate, while Rachel doesn't have that problem since wireless jamming doesn't affect her ability to coordinate with her dogs and her people are in the basement.
Also, it's not going to be the Empire's A-team. They are attacking an unmasked Ward at home. It would likely get a pass if she was still a villain, as one could argue that the farm is her "base". This whole thing is a desperation play by a cape who hasn't adjusted to the new world order, and minions too dumb to take one of the many, many off-ramps on offer.
