I need help planning a trip with my mom

Hi all. I'm planning a trip to WDW with my mom for her birthday, she's turning 66. She's never been, she can't walk ALL day so we'll take it easy and she doesn't like rollercoasters.

We'll be there sept 4-9. We arrive late on the 4th so I'm thinking Disney Springs, La Nuoba, the broadwalk, maybe watching fireworks from the polynesian. In summary, no parks for the day.

Her actual birthday is on Tues, so I've made lunch reservations for BOG and we're spending the day at MK.

And here is where I need your help. I was thinking of spending either Mon on Thursday at HS, mostly due to Fantasmic, but can you really spend a whole day there? We went last year, rode everything, saw all we wanted, and it still was a very leisurely day.

And what about AK, with the new late opening times? Are there enough activities to keep us there all day?

Any tips for a trip with my mom would be extrmely helpful. Thank you!