I have no clue about women’s bikes, or do women even need women’s bikes?
Want to get a modern CF disc brake Di2 (probably Ultegra) or SRAM electronic bike.
Tiny size, like a 50 or 52.
Oh and bigger tires
My GF is a serious cyclist but doesn’t give a shit about kit, she’s riding around on a rim brake bike with crazy gearing and 23 mm tires (and no room for bigger, maybe 25s?) and stretched out like she’s riding a TT
yes and no - looking for smaller sizes, might help if you look for some women’s specific, but anymore they’re largely the same with maybe narrower bars and different colors.
I would look at canyon as far as best bang for your buck. you could get her a very, very nice bike within your budget (i.e. carbon wheels, di2, etc). the sizing is a bit weird so check the geometry charts - guessing she’ll need a 2xs (just checked the ultimate - 516 mm top tube on the 2xs).
And Canyon makes bikes down to tiny sizes and switches to 650b for the smallest so they can actually have the reach vary throughout the range. I don’t think you need something this tiny, but for reference, my wife’s 3XS Canyon Endurace can fit 32mm 650b tires (Conti GP5k is available in this size). It’s essentially a 46 cm frame with a 73.5 deg seat tube angle (most brands, a bike this size has a 75 deg STA), 494 stack, 346 reach. They’ve changed sizing a bit and the current version is 510 stack/350 reach.