mecabq

Definitely worth it and easy. To see some street life and local cuisine, you could take the Metro to Deira and wander around. The waterfront and spice souk/gold souk will be pretty much closed, so the interior areas can offer this. Maybe take the metro to Salah Al Din or Al Rigga (the former would require a transfer) or, with three people, a taxi is not much more expensive (probably around AED 40 with the AED 25 flag drop from the airport). I am fond of the restaurant Calicut Notebook, a south Indian mid-scale place. You could walk from there down Muteena Street or Salah Al Din Street in the direction of Fish Roundabout and Baniyas Square, which are downscale local areas that are open late. There are lot of hotels (from dumpy to five-star) where you can have a drink, or shisha cafes if you're into that. You could duck into the Al Ghurair Mall if you need a rest with A/C. As an alternative, the other side of the creek offer some more upscale touristy areas (either Al Seef or the areas around Bur Dubai Abra Station).

In any case, it will be very easy to find a taxi back to the airport at any time. The hop-on buses probably don't operate at that hour. You could arrange a mini-tour from a desk as you exit the airport if you wanted to see more places.

You won't see very many women wearing shorts, or many groups of women at all in Deira, but it's fine.