OP, because there is a 14-year old in the group, the kids will be fine eating alone. If they need help with calculating a tip (but it doesn't sound like they will!), they always have suggested tipping percentages at the bottom of the meal bill (15%, 18% and 20% I believe is listed)
Also, while you continue to look for a table for 5, you could also look for a table for 2 around the same time. If you can snag that, you can always ask at the podium if you can all be seated together. Even if they can't put you together, you would all be in the restaurant around the same time if you would still like to eat there.