I found various translations for the word 世話焼き: nanny, busyboy or busybo**d**y. Since I'm trying to read シロクマカフェ I would prefer busyboy, but which one's acutally correct and how could I've find out myself? I couldn't find the word in my dictionary.
Pulled partly from 三省堂 大辞林 and paraphrased.
1.a. To like or enjoy taking care of others.
1.b. Wanting to take care of others beyond what is necessary; burdensome to the receiving end.
* This definition spans various industries, environments, and situations. For example, a caretaker in a home, an organizer for an event, a person in charge of doing miscellaneous tasks for a sumo stable or arena, etc.
Now, I don't know what シロクマカフェ is so I can't give you an answer in terms of the literary context.