Hi Rolinda,
I do have experience with a bed wetting alarm but with my son. Before I say anything else about it I think you should double check with your doctor since your daughter was dry at night for a while and then began wetting again. I think this pattern is more likely to be a sign of a medical problem then a child who never stops wetting the bed at night. Does bedwetting run in your family or your husband's? If it doesn't I think I would push a little harder to make sure there isn't something else going on.
I don't want to discourage you from using an alarm and I'm sure you've read lots of reviews for alarms. Some of them are absolutely glowing, but others are very discouraging. In my experience the alarm worked, but it's best if you know what your in for. The alarm is only part of a behavior modification program. Your goal with it is to teach your child to hear or listen to her body's signals while she's sleeping. It's far from a magic pill. It worked wonderfully for my son and I highly recommend it, but it took months and was hard work.
When my son was in 1st grade he decided he wanted it to stop wetting the bed. He wanted to be able to sleep at a friends house without wearing a Goodnights. I don't think it would have worked without a strong desire his part to stop wetting the bed. My son is a very deep sleeper and I ended up sleeping on an air mattress on the floor of his room for weeks. In addition to the alarm we limited his liquids after dinner, made sure he was drinking a lot during the day, and went through bedtime practice visualizations every night. He had a sticker chart and when he had 21 consecutive days he could stop using the alarm. We had a Malia alarm that attached to his underpants. The rest of it was pinned next to his pajama shoulder. It vibrated, flashed and made a loud noise when it went off. That didn't wake him at first so I needed to jump up and get him to turn it off and go to the bathroom.
This went on twice a night for the most of the first week, before he heard the alarm at all. It ALWAYS woke me up - even when I had (finally) returned to my room. It was very worth it because it helped my son work through a difficult problem, but it was like having an infant all over again. Things only got better very slowly... he stopped wetting 2x at night, then the spots got smaller and then he started actually having dry nights for the first time in his entire life. He started using the chart in May and used the alarm all of the following summer vacation.
I really would suggest taking your clues from your daughter. She is going to need to be totally on board with this. I can't remember the name of the book we used to guide us, but it was very good and I seem to remember it was the only one written to the child. I think they recommended waiting until the child was a little older before trying to use the alarm. How do you feel about getting up a couple of times during the night to help her? My son wasn't waking up completely and I was concerned about him having a different kind of accident sleepwalking to the bathroom. I'm fairly sure he still sleepwalks to the bathroom, but he's almost 11 and has only wet the bed 2x in the last year. I was in middle school before I stopped wetting the bed completely so I consider this a major victory for him.
Whatever you do, there are saddle pads for the bed available on-line. I loved these I didn't have quite as much laundry to do - I would recommend them. I also used the disposable incontinence pads sometimes. My son is a very active sleeper too, so we masking taped them to the sheets. I always had a second complete set of sheets sitting in a laundry basket outside of his room that I could use in the middle of the night to change the sheets without turning on the lights and waking us both up any farther.
I don't have experience using the alarm with a girl, but I always assumed it would work just as well with the sensor clipped a little lower on her underpants. My daughter just turned 8 and although she still wets occasionally, I don't think she does it frequently enough for an alarm to help. She seems to be growing out of it on her own.
Good luck,
K. L.