They aren't technically tickling her, just extracting salt from her sweat. The innocent intention doesn't help the reality though. Poor Mrs. Hudson, her armpits and inner thighs are her weak spots, too.
(oc) 🎶Sing it with me... Put your right thumb in, & pull it up & out. Grab a nip with your left fingers, & twist it all about. Do the hokey pokey & spray me with your spout.😆