Hello Samantha,
How awesome you and your family will be coming from South Africa to Disney World! It's sure to be a magical vacation for all of you!
October is a wonderful time of year to visit. Crowd levels tend to be really manageable. And on many nights, there's
Mickey's Not So Scary Halloween Party (MNSSHP)...my favorite! MNSSHP would be a great place for you to meet up with another family. You do need separate admission tickets for MNSSHP (apart from your normal Park Tickets) but that works out in case your friends were not planning on purchasing Magic Your Way Tickets for themselves.
If the other family would rather not buy tickets for MNSSHP, you can always suggest meeting up at
Downtown Disney. There's no cost to enter. And there's plenty to do for the entire family. You can walk along the water, shop the Marketplace, and there are many restaurants to grab a bite to eat.
Raglan Road Irish Pub is one of my faves!
Hope this helps. Safe travels this fall!