Not Sure If This Is Discharge or Pee Stain? Moms Advice Needed, Please?

All of the girls in my family have had "girl" problems since toddler age! It could be discharge, or a slight yeast infection. My personal advice would be to try to address it by diet/ laundry soap & bathing BEFORE talking to doctor. Because of my problems, my ped. insisted on an exam at 5 years old. It really traumatized me, and I was terrified of doctors for a long time.
Same scenario with my neice. Even if she's not complaining of it bothering her, she may still have an imbalance. Things that help WITHOUT medication/ toddler female exam: 1) probiotics! it's the new craze, but really nothing new. Lots of Yogurt & you can even get probiotic supplements for her 2) Free detergent. Get rid of the scents & dyes. Gain is the absolute WORST 3) baking soda baths. We put a cup of baking soda in every single bath. 4) flushable wet wipes. Make sure she is getting wiped very well each time she pottys!

Smell it. If it doesn't smell like pee, it's just vaginal secretions, and nothing to worry about.

It took until my 20's to know that was something that didn't have to be. I wore panty liners every day from the time I knew what they were. Turns out I had over active mucus glands. Awesome Dr. noticed it during exam, asked if I had frequent yeast infections. Answer: yes! one right after the other since I was 12!
Not saying that is what it is. Probably normal, but just in case you wanted to have it checked, it's a possibility.

My daughter does too sometimes and she is 4 as well. As long as she isn't complaining I wouldn't worry about it. I've always thought it was normal??