Toddler with vaginal discharge

When changing my 18 mo old girls diaper, I noticed a small yellow streak on her diaper. When wiping her I saw some clear/white discharge. I’m going to call her ped tomorrow but in the meantime anyone have that happen to their LO??

I’m not sure what it could be. We always keep her super clean. Bathe regularly and changing diapers very frequently (even if it’s clean).

There was one morning where I changed her when she woke up and there was poop (not sure if she pooped overnight??). Maybe it’s an infection from that? ☹️

She doesn’t seem to have any other symptoms like itching or anything