How many characters can we absorb at a time?
In working on query letters and pitches, I've become conscious of the "name soup" that can happen when too many characters are crammed into that tiny space. Like a party in a tiny apartment, there's no elbow room and no way to keep track of who's who.
What about in the novel itself, though? How many new characters can we introduce before the reader needs time to breathe and process?
I suspect part of the answer lies in how we introduce them. Don't start a ticker-tape parade for a minor character who serves a limited function for a few pages. Conversely, if the character is important, they need to stand out.
I wonder how much genre and audience play a role. Do readers expect a large cast of players in certain books? Readers of sci-fi and fantasy will be more prepared for strange names than readers of a modern-day crime thriller. What about the number of names to keep track of?
Speaking of strange names, we can make up the craziest names we want, but let's make them pronounceable. Even if the reader might assume a different pronunciation than we intend, it needs to be possible to come up with something. Too many fantasy novels evoke my "Pat, I'd like to buy a vowel" reaction.
Now that I've posed the question, I'm going back to check the first scene at the foster home. Have I thrown too many names in too small a space? Hopefully not.