Stella, your overall frugality makes important things like visiting your aunt possible. It can be hard though to switch from black-belt-frugality mode to still-careful-but-enjoying-the-fruits-of-my-frugality mode.
For the reunion, if you can grill in the park, you might be able to cook the meat as part of the activities of the day. Often hanging around the grill allows people to interact who might not easily otherwise. A favorite when we do this for large groups is chicken marinated in italian salad dressing and then grilled.