Calendar management for elderly business owner

Hi everyone!

Once a week I help an elderly client run her astrology business. Right now, clients fill out an interest form on her website (or they email her directly), then she and I manually respond to and schedule each one. Her readings are done through FaceTime, phone, or Zoom, but if done through Zoom, the clients must send the link themselves because she isn't comfy being responsible for all the host controls.

While our current system works, it is inefficient, especially because I only help out once a week. She also does most everything on paper (including maintaining calendar), so there's not a central online location to ensure all clients are being handled appropriately, to keep up with her schedule when I'm not meeting with her, etc.

I am looking for a super simple calendar management program that is elderly-friendly. I've looked at a few suggestions from this subreddit, but I haven't felt like I've found a good fit. Some things we are looking for...

• Ideally this program can send automated email reminders to clients
• This program allows her to confirm the time herself rather than have the client schedule a time based off a pre-set calendar (like how it works on Calendly, for example)
  • We want to avoid having her set her calendar availability each week, but it might be unavoidable.
• Not necessary, but it would be cool if this could be embedded into Squarespace somehow. Or at least an easy link to send to clients.
• Not necessary, but it would be a perk if the program had a native video call system so she wouldn't have to worry about Zoom links and all that stuff

Thank you in advance! I have learned a lot from this subreddit!