Would it be weird to add a girl on facebook who I kind of know?

She and I talk and have proper conversations everytime we see each other. She and I know each others name. By sheer luck I accidentally came across her on my people you may know list on facebook cause she has 1 mutual friend of mine. Would it be weird to add her?

She is a coffee shop lady and I'm a customer. Would it still be weird.
Would it be weird to add a girl on facebook who I kind of know?
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