I have a hybrid, a Diamondback Vital2. It's a good comfortable bike with a relatively lightweight frame, and is normally under $300 at Dick's. It is NOT a hardtail; there is seat and fork suspension, and also a chain guard, so that you can ride it in jeans without tearing them up. The tires on my small frame are 27", which makes it look oddly tall for a small-frame bike.
A "hardtail" bike has a fixed seat with no rear suspension. The saddle itself is no big deal, because you can always buy a different saddle to put on it, and adjust the tilt and rise of the saddle to better fit your body. (Speaking of that, be sure to buy the proper frame size. Lots of shorter women ride too-large frames not knowing any better.)
Just to be clear in case anyone has the same confusion as my DH did, in bikes, "hybrid" means a cross between a road bike design and a mountain bike design. It does not refer to a bike with a power-assist electric motor; those are called electric bikes. Hybrids have medium-thick tires and an upright stance; you don't ride with your upper body parallel to the ground.