Meaning
Combination of two words: Sephora and Kids.
“Sephora Kids” is a term coined to refer to pre-teens around 7–12 years old who swarm into beauty stores like Sephora and Ulta to look at or shop for products that typically target older teenagers and women.
Source:
Further Reading:
CNN Business – https://edition.cnn.com/2024/03/12/business/sephora-kid-tweens-skincare-obsession/index.html