Mealworms are not a good staple feeder or even a good treat for any age or size of bearded dragon, they are full of fat and have very little nutritional value, and they are actually mostly hard, chitlin shell, and this can cause impactions, especially in small babies because of their size and the fact they can get clogged up with undigested shells. If she only ate 3 mealworms, and they weren't very large mealworms, and she chewed and swallowed them without choking or vomiting, she should be fine. She may pass them undigested, or you may see little bits of undigested she'll come out when she poops, that's normal. If she starts straining or has trouble pooping in the next week then you'll want to drip some prune baby food mixed with plain, canned pumpkin (from the canned veggie aisle at your grocery store) and a little unflavored Pedialyte onto her snout twice a day, using an eyedropper or an oral syringe. If you mix all 3 up and microwave it for a minute, then mix well and test it on your wrist like a baby bottle, so it's warm but not hot, and let him lick it off, then drip some more, luck, drip, etc. Give him as much as he'll eat, then let him bask for an hour or two, then a warm
bath, it should act as a natural laxative and allow him to poop. But you only need to do this if he doesn't poop within the next week. I'd just give him a warmer than normal
bath once a day starting now until he passes the mealworms, he'll probably pass them without any issues within the next 3-4 days, but now you'll know what to do if he doesn't.
You definitely need to find him a nutritious, live staple feeder that you have regular access to ASAP, because from the time they are babies up until a year old, they eat very little if any veggies or greens, most eat only live insects, and they need a TON of live insects every single day, 2-3 times a day up until they are a year old, because this is when they are growing and developing. He should have his UVB and his bright white basking lights on for 1-2 hours each morning BEFORE he is given his first feeding session of the day, which should last for 10-15 minutes, and he should be given as many live insects as he wants, fed them one at a time until he no longer wants any. Then he should have at least one more 10-15 minute feeding session each day where he is allowed to eat as many live insects as he wants to, and then both his
UVB light and his bright white basking bulb should be on for at least 1-2 hours after his last feeding session of the day before you turn his lights off for bedtime. This will allow him to properly digest and absorb his food. If you can get a 3rd 10-15 minute unlimited feeding session in the afternoon every day, so he has 3 unlimited 10-15 minute feeding sessions every day up until he's around 6-8 months old, at which point you can cut back to 2 unlimited, live insect feedings per day, it's much better. Also, his lights must be on for at least 14 hours every single day, both his
UVB light and the bright white basking bulb.