If you have the urge to laugh and try to stop yourself but make a slightly sneaky noise with your throat for a second, without smiling, does that break your prayer?

I have to ask whether a female can laugh in presence of non mehram men. I used to think that it's not correct as females must use stern or strict voice with men as is mentioned in Quran 33:32. In this verse, laughing is not mentioned but it seemed obvious to me that laughing is going against being having stern voice. But recently while discussing this with someone, I realised that I may be wrong. He said that talking in loving manner is wrong but laughing is not wrong and it's not non-stern thing according to him, specially when the conversation is related to work only [casualness pops up even in work related talks]. So what's correct and how is it derived? And what is its level of importance like farz, wajib, recommended or optional? Jazakallah.

Salam alaikum, this question seems weird but listen to my story. Every day after coming back from school I look at an image of big chungus and laugh hysterically for around 15min, it's the only time of the day when I feel happy. One day my mother insisted on knowing why I was laughing, after she saw the picture of big chungs she immediately turned off my computer and told me that what I was doing was haram and she refused to explain why.

During the Eid prayer I laughed because of something a little girl did. It was a very quiet laugh. Do you know if I have to make this prayer up? Should I make it up at home?