Hi G.,
Like your doctor said, most night terrors are out grown; however, there is usually a stimulus that causes them. At 2, I doubt there is any stress (which can cause them in older children) so environmental toxins can be a primary culprit. Cleaning supplies and bath and body products can cause neurological damage and can cause things like night terrors, nightmares, child behavioral disorders like ADD and ADHD and even memory problems. The main problem with your average product at Wal-Mart (Johnson and Johnson type products) or the grocery store is that it has an "allowed" limit of toxin. When used in combination of other things with "allowed" limits, the limit has increased. This is not to mention the combination of toxins that outgas and contraindicate just like pharmaceutical do.
The other issue that usually causes night terrors is lack of sleep. So you have a vicious cycle here with night terrors keeping her awake and causing lack of sleep. Some doctors will tell you it is caused by overstimulation. That can be true. This leads to either behavioral issues and habits or back to environmental toxins. Both stimulate the neurological system. However, behavioral stimulation will eventually settle as the child does.
I think detoxing will help a lot, ESPECIALLY by changing to a laundry detergent that is considered non-toxic to humans. (There are a lot of things labeled non-toxic that are only considered non-toxic to the environment.) If this is not the culprit, then no harm has been done. Detoxing CAN be simple and it can be inexpensive to. If you want to give it a try, I'll be glad to help.
God bless,
M.