Hi shelby. I've flown a lot recently, mainly for business, but also for pleasure.
Check the particular rules by going to your airline's Web site. But, in general, there's something in place called 3-1-1, meaning that if you carry on any liquids, they all need to be 3 ounces or less, in one clear, quart-sized ziploc bag, and one bag per person.
The 3 ounce bottles must fit inside the ziploc and positioned so that the bag lays flat. In other words, the bottles should be side by side rather than one atop another. The bottles should also be marked with the capacity, if possible.
Here's what I do: I have a quart-sized ziploc that I fill with a 2-ounce container of saline solution, a couple of pairs of extra contact lenses, 3-ounce hand sanitizer, and sample sizes of toothpaste and conditioner. The ziploc is in the top of my carry-on bag. That way, when I get to the security line, I can easily remove it and place it in one of the bins they provide, as this bag needs to go through the x-ray machine by itself.
With five people, you'll be able to carry on quite a bit.
When I've traveled on longer trips, I've placed shampoo, mouthwash, etc., inside checked luggage, inside a couple of sealed bags so that all would be protected if it sprung a leak. The bottles in your checked luggage may be larger than 3 ounces. Again, check with the airline for particulars.
Hope that helps. I'm happy to answer any additional questions before I fly out yet again next week.