Leslay's bullying/infatuation to me seems to stem just from her insecurities about her own body, wanting praise from people for the outfits that she wears, commenting on her own breasts when there's people in the house with better ones will pretty much kick her when she's down, and to combat that she's singled out someone who doesn't necessarily get on with the whole group and proceeded to bully them as that's pretty much the only way she can one-up someone in the house. If she's to stand any chance of surviving in the house Leslay needs to grow up, not out.