Maybe that's a British saying, or perhaps an outdated way of saying the AmE "touching base with".
'To touch base with someone' means that you speak with them and let them know what's going on lately or what your plans are. She's saying that writing makes her as happy as getting together and talking with a great friend (if the 'touching base' meaning is meant, which it sounds like it is).
"I'll touch base with you before I make any definite plans." (I'll not make plans without informing you first)
"I hadn't seen my friend in a long time, it was great to touch base with her again."
(not a teacher, just a language lover)
Student or Learner