Tara King was a Steed girl.
So far, the John Steed sidekicks named are:
1. Cathy Gale
2. Emma Peel
3. Tara King
There are a few more, especially if you look at the "new" ones.
As far as the actresses that were Bond girls that were also John Steed's sidekicks, you [the collective you] have named:
1. Honor Blackman
2. Diana Rigg
There is at least one more as far as I know.
To CM, I don't remember Terry from Fawlty Towers. I'll have to check it out again.