If you can ride a hybrid, you can ride a road bike.
Learning to use the slightly different shifters is a matter of minutes.
What might need to be dealt with is posture and upper body strength.
The bar height you can tolerate/enjoy depends on your flexibility and fitness.
Many road bikes are sold with the bars set quite low, which might not work for you.
It's possible to change to "riser stems", or add "steerer tube extenders" to bring the bars higher/closer.
There are also adjustable stems that swings the bars up-and-back in small steps.
A bit heavy, ugly and prone to creaks but functionally OK.
The best thing is if you can buy a bike that comes with the "steerer tube uncut".
A good shop will be able to help with this, and talk you through the different options.
Edit:
If she's strong enough to use her arms to get out of a chair w/ arm rests she doesn't need to worry about the pressure on her wrists while riding.