I don's know your exact situation, and I know that for me saving money is very important and every penny counts, but when it comes to travel on Frontier with families, I would highly advise purchasing one checked bag per family instead of trying to cram everything into personal items.

Remember that everything you carry on the plane has to go through the TSA checkpoint, which means no liquids, gels, or toothpastes that are more than 1 ounce. This means you'll either have to buy small sizes of you personal toiletries, or put them in smaller containers. It's a hassle for sure. If you check it, you can check your full-size toiletries from home each way, no hassle.

Also, if you check a bag, it can weigh up to 50 pounds, which is more than enough for two adults and a child on vacation, we have found. We use a good-sized dufflebag and find that it even leaves enough room to pack any souveniers we buy and take home with us.

For this reason, I think the $25 each way checked bag fee is really worth it. Remember, you can buy just one bag for all your connected tickets, you don't have to pay $25 per person. Chances are since you are flying with Frontier you saved a lot of money already on airfare, so really consider the $12.50 per person for two or $8.33 per person for a three way split as not that much for the convenience of not having to pack all your toiletries in the carry on.