Cat-themed birthday party for a 9 year old

It might be a bit too far, but my daughter is going to a cat party at the Marin Humane Society in a few weeks. It's a super nice facility located in Novato. 

Check out Cat Town Cafe!

https://www.cattownoakland.org/reservations?gad_source=1&gclid=CjwKCAiA…

There are other cat cafe around the bay too.

Depending on how big of a party you're planning you could check out Cat Town in Oakland (https://www.cattownoakland.org/reservations) or KitTea in SF (https://www.kitteasf.com/private-events).

I don't know whether Cat City in Oakland will let you have a party there, but they may know where you can. 
https://www.cattownoakland.org/reservations?

https://www.cattownoakland.org/ Just recently heard of a family attending a birthday for their child 

I doubt I'll be the only one with this response, but try Cat Town on Broadway (near Pill Hill), and see if their cafe still does social events:  https://www.cattownoakland.org/reservations   If not, it might be possible to just visit the cats, and then go somewhere nearby.

I'm not sure how many people they can accommodate, but Cat Town (https://www.cattownoakland.org/) might be able to set you up if it's a small group. When my son was about that age we went there (just the 2 of us, not a whole party) to play with the kittens and he had a great time. They have a cafe part next door (no cats in the cafe). If they can't host they might have some other ideas for you to pursue.

How about cat town? :)

We love cats too!  I volunteer at Cat Town in Oakland, and although they don't have formal "birthday parties", you can book an hour long visit with the cats.  Generally folks will reserve spots for all of the guests, and afterward, have cake and beverages in the attached cafe.  Links are:  

https://www.cattownoakland.org/

https://www.cattownoakland.org/reservations

...and happy birthday to your son! 

Cat Town! On Broadway. They are fantastic and do private parties. Check their website