I really like the name Ada, and would pair any classic feminine or masculine name with it. For example,
Ada & Benjamin "Ben"
Ada & Oliver
Ada & Charles "Charlie"
Ada & Colin
Ada & James
Ada & John "Jack"
Ada & Ruby
Ada & Charlotte
Ada & Grace
Ada & Eleanor "Nora, Ella, or Ellie"
Ada & Lillian "Lily"
Ada & Katherine "Kate"
Ada & August - nice, but not my favourite. August is a bit trendy 7.5/10
Ada & Felix - cute! 7/10
Ada & Henry - very lovely and distinguished. 8.5/10
Ada & Ezra - not a huge fan of the name Ezra, but it's ok. 6/10
Ada & Theodore - ADORABLE. Theo would be such a great name for Ada's brother since both are classic, decidedly masculine or feminine rather than unisex, and are not overused. Love this set. 10/10
Ada & Violet - nice, both names are very pretty 8/10
Ada & Alice - lovely! both are great names that pair together well, are both classic and feminine, but aren't too close together. They sound like they could be sisters :) 10/10
Ada & Matilda - Love the name Matilda, but I don't love that the two names both end in "da". 6/10
Ada & Olive - Not a huge fan of the name Olive, but it's ok. Ada is so much prettier. 6/10
To go with Ada, I like Theodore for a brother, and Alice for a sister. For middle names, I think Theodore Henry & Alice Matilda would be stunning and just too perfect for words! :)
Hope this helped!