Purdah

Free mixing with non-mahrams

Q: I am a girl and two of my girl cousins recently got married and their husbands mix freely with them in playing some games such as cards or monopoly for example. They always force me to play with them and I try not to play with them anymore.

I heard that free mixing is haraam and I tried to tell them but they mocked me and said that we are just playing cards and we are not sitting near each other, there's a distance.

I wanted to ask what should I do? Am I sinful for playing with them because their husband's aren't my mahram although we keep distance? How can I convince them if it is haraam?

Having meals with non-mahrams

Q: Is it permissible for me to sit and eat with my girl cousins while her father, mother, brother and my mother are also seated there.

Also, can I say جَزَاكَ اللَّهُ خَيْرًا and speak about general things like Madrasah with her mother, who is my mother's brother's wife while they are wearing abaya and scarf but part of their hair or neck is exposed?

Woman conducting an online course

Q: I am a woman and need to earn money. I have developed an online course that will not reveal my face but I need to record my voice explaining the content, and I cannot limit the course to only women (there is no way to do this on the online course platform). Though people will hear my voice, no one will know me. Is this halal?

I may also be able to use a software to change the pitch of my voice slightly (lower the pitch of my voice). Is this better?