My mil let my LO tried lemon. In general we let her do what she wants since she hardly get to see the LO plus she is a nurse. When I told my mum, she reprimanded me and said it would cause gastric. Would it?

It's okay to consume lemon in moderation unless she gave lo the whole lemon. Hahaha which i doubt so. Its good and recommended for baby to try out all kinds of food with different taste and texture. Dont worry too much about it.