The parents , and mostly the mother , is the most important figure in boosting the morale of her children.
Telling them that they are loved , beautiful , capable .. That they make you proud , happy , etc.
These are all essential. In fact , there are stories I have read on this forum of women never being told that they are beautiful , ever in their lives. When really ( from an Islamic perspective ) , her family should be encouraging their self esteem or else they may go and seek it from haram sources.
From what I have heard in general – and feel free to correct me , but things get problematic when we praise spouses / children beyond what is acceptable. For example , telling your spouse ” You are the most beautiful of Allahs creations. ” or things of that nature.
Allah knows best