You may check out venues like Shakey's Eton Centris or for a bigger venue, there's Elements, also in Eton Centris .Bunny Baker along E. Rod. also offers a very dainty set up for any occasion. Quezon city Sports complex might be an option also. Sharing this with you for more party venue options: http://mscaye.blogspot.com/2014/03/party-venues.html?m=1
Hi, if you like to hold in indoor area and let your child has great fun then u can explore explorerkid. Find out more at http://www.explorerkid.com/birthday_parties. Otherwise, you can explore eatplaylove cafe at http://www.eatplaylove.com.sg/?page_id=17. Though not really North, but is centralised and can occupy your child with craftwork.
How about a function room in a community centre? There are plenty of community centres in the Northern part of Singapore and those are usually big enough to host 100 guests. Price wise, the rentals are pretty affordable, ranging from $50-$100 an hour for rental.