What to wear for sons graduation

[PoliticallyIncorrectHitchling]

My son has finally passed his Engineering degree and now I need to figure out what to wear to the graduation ceremony. I really dont know what to wear. I am size 14, curvy. Need a dress with sleeves and has to be just below the knee.
Please can someone suggest some alternatives? Can spend upto 350 pounds.
I have chosen 2 options:

https://hopeandivy.co.uk/collections/new-season/products/the-claire?variant=44043659378942

and

https://www.esprit.co.uk/p/satin-midi-dress-033EO1E324.html

I prefer the first blue one, with my Son’s graduation there was a lot of waiting around on the day so I think the second one would cease after a while. I wore a black trouser suit with a turquoise coloured blouse.

I went far too dressed up in a dress and jacket slightly wedding style. Wish I just got a normal smart work clothes or to be honest anything

Both addresses are nice, I would recommend not buying anything new.

Dresses *

i will need to buy these as I dont have them yet. For some reason, I am finding it hard to decide