Wide pictures in gallery much smaller than vertical pictures

Site URL: https://www.rwpho.com/

Hello,

I would like to be able to have the wide aspect ratio pictures on my website be displayed larger than they are currently. They look very small compared to the vertical ones. Is there any way to do this? I am using wells template. Also, would love to know  if there  is a way to individually edit  gallery options. I would like for the landing page  gallery  to be two images wide when viewed on a regular size computer, but one of the other pages only one image wide.

Thank you so much for any help!