Get something with no suspension (lighter weight, less to go wrong, not needed if not riding off-road)
Get something with smooth tires. (knobby tires have much higher rolling resistance and worse traction on pavement)
If you find a bike you like and it happens to have disk brakes, OK, but I would not consider them a selling point. Disk brakes add weight, expense, and have few advantages on-road, and virtually none if you don’t ride in the rain. Modern rim brakes on aluminum wheels work fine, weigh less, and are cheaper. Disk brakes require a heavier, stiffer fork that gives a harsher ride.
I will go against the grain on the dropped bars. They are great for an experienced cyclist in good condition. * They are fairly useless for a casual cyclist in less than great physical condition, and stand a good chance of souring someone before they get to the point of being able to exploit the advantages, They are likely to ride on the flats for comfort, with poor steering leverage, and no access to the brakes, and using the brakes from the hoods on dropped bars is awkward enough that it has lead to crashes for new users. Straight (mountain bike style) bars are better, but old-fashioned swept handlebars will be more comfortable.
Biggest newb mistake is probably seat too low/bike wrong size. This makes it much harder to pedal and can lead to knee pain or worse. A decent bike shop will put her on the right size bike and adjust it to fit her proportions. If she can put her feet flat on the ground while sitting on the saddle then the seat is too low, unless it is a dutch style bike or semi-recombent like ** stoid** has.
The more speeds it has, the fussier it will be to shift and keep adjusted, the faster the chain and other parts will wear out, and the more expensive parts will be. 9 speed rear wheels are a pretty good value point these days. If you go to 10 or 11 rear cogs it will add a lot of expense or be total crap.
*You power a bike by pressing down on the forward pedal. The harder you press down, the more of your weight you need get over the front pedal. Since your butt and other leg are behind the front pedal, you need to lean your upper body forward to do that. This also helps pre-load your hamstrings which can add power and improve efficiency. The harder you are pedaling, the farther forward you need to lean. This is why road racing bicycles have dropped bars…they allow you to lean way forward and pedal really hard. If you are not in good enough shape to pedal that hard, then you end up putting a lot of weight on your hands, leading to sore wrists and numb hands. You will notice that even TDF riders are not on the drops for most of the race…only when sprinting really. Drop bars are also helpful for cutting air drag at high speeds or when fighting a headwind. They also offer multiple hand positions, which can be helpful on hours long rides. Casual cyclists don’t get much use from these features.