Baby/ toddler girl's vagina

   My 1.5 year old's vagina always looks red. Not the outer part like a rash but the inner labia, the bottom part of the hole, and the area surrounding it. No one has or is hurting her since she's with me 24/7. She's gets her diaper changed pretty often. At least every 2 hours but sometimes 3 hours if we're out somewhere. One doctor tested her for a yeast infection and gave us a yeast diaper cream to use while we waited for the results. It didn't help for the couple days we used it and her test came back negative so she doesn't have yeast. I'm wondering if it's just her skin pigment but I feel like it looks irritated almost. Mine is really pale pink and never red so I don't know. She also seems to smell a little like pee down there all the time even right after I've wiped her or bathed her. She gets a bath every day and I always clean her down there so hygiene is not the issue. 
I don't believe I'm cleaning her too much, I basically just wipe her when I change her diaper and then use a wash cloth to gently clean her vagina and booty during bath time. We use all natural products in our home so I don't think it's soap or detergent irritation. 
And no I don't clean inside! But I do very gently wipe the crease between her labia minora and labia majora but not every diaper change. I mean, I'm pretty sure you need to do that, especially if they have a messy poop. 
LITTLE UPDATE: in case anyone reads this and wonders the same thing about their daughter. I had an OB appointment with the same OB whom I've seen for 10 years and saw me through my pregnancy. I told her about my LOs vagina looking red. She took a peek and said its just my daughters pigment. She said everyone is a different color, even mothers and daughters and that it may change as she gets older but that the red color isn't irritation and she looks healthy.