I don't know why it's so hard to find plain black leggings for NB these days. Luckily I found them and they are great! The quality seems decent and comfortable for my girl.
Kid Nation Unisex Heather Charcoal Girls' Clothing for Leggings
52 Review
Adorable and comfortable Splendid girls' leggings for kids and babies
80 Review
Spotted Zebra Girl's Disney Star Wars Marvel Frozen Princess Leggings: Unleash the Fantasy!
46 Review
Lilax Girls Basic Length Leggings Girls' Clothing in Leggings
52 Review
Dancina Toddler Leotard Flutter Sleeve Girls' Clothing for Active
55 Review
Thermajane Girl's Cozy and Comfy Thermal Underwear Long Johns Set with Fleece Lining
46 Review
Tommy Hilfiger Girls Crop White Girls' Clothing
54 Review
Amazon Essentials Little Short Sleeve Leotard Girls' Clothing for Active
61 Review