Questions about Bearded Dragons?

I just got a female Bearded Dragon. She is a baby and is approximately 7 inches long. I currently have her in a 20 gallon tank, but will be upgrading to a 50 gallon tank in a few months. I am using (2) Flukers Mini Sun Dome lighting fixtures with (1) Zoo Med Baskin Bulb 75W and (1) Flukers Sun-Glow Coil Lantern bulb 20W with a UVB from 290-310nm. I understand that she needs a day time/night time gradient, so do I turn off both the UVB and baskin bulbs at night? I have a cheap Critter Culture Night Heat Bulb 75W that was purchased a few months ago but never used. Will that keep her warm enough tonight until I can go to the pet store tomorrow? Also, any suggestions on the best night time bulbs would be appreciated. I just don't want her to get too cold tonight lol. I have a stick on thermometer on the hot side of the tank and it currently reads 90 degrees but I just read that they are not always accurate. I will be purchasing either a digital probe thermometer or an infrared temperature gun tomorrow, so any suggestions on the best brands would also be very helpful. Thanks so much.