As salamu alaykum sister,
Often times reverts do run into problems with family as Islam is a very different religion and way of life to them. While I am not sure how long it is that you & your husband reverted, it could be that your in-laws need more time adjusting to your way of life. Insha’Allah, they will find tat Islam provides a complete and moral way of life by watching you and your husband interact, live your lives, raise your children, and treat them.
It seems that they are trying to comply with your wishes (by not drinking alcohol around the children, serving them halal food, etc.) . The remarks about your children “flirting” or being a “tart” can be harmless expressions which they think are cute, but are offensive to you. I would kindly suggest dear sister, that you give them credit for the progress they have made in accepting this “new way” of life-with it’s restrictions upon them as grandparents in regards to their way of life.
They are slowly making changes to make happy relationships, therefore I would advise insha’Allah to pick very carefully what you get upset about. It seems that they love you very much, but if you keep pointing out everything that is upsetting you or not acceptable, they may begin to think Islam is a religion of extremes, which it is not. In the beginning, it may be overwhelming and discouraging to them if you point out every error you perceive, as they appear to be complying with the major requests such as no alcohol and serving your children halal foods. They don’t have to do that.
As far as your in-laws not like being told what they can’t do in their own home, that is natural sister, would you like it if your mother in law came in your home and started telling you what you can, and cannot do? If you did not want a picture of yourself displayed without hijab, why give it to her? Naturally, parents and in-laws who love their children and daughter-in-laws often like to display their pictures on walls. This is very common in non-Muslim families.
Sister, sometimes being a Muslim means being empathetic, compassionate and patient. It often means, especially where family is concerned “picking your battles”. From what you wrote, it does not seem like there are harming the children’s spirituality, but rather assisting in keeping it halal as you requested. It does not appear that they are doing any major haram acts, nor resisting all of your requests, in fact they appear to be complying, but they also seem frustrated at the many demands they are receiving.
I would kindly suggest dear sister that you focus on the positive things that they bring to your children and family unit. I would also kindly suggest that you try to ease up, let them know that while yes you are Muslim, you still love them and respect them. The more you focus on getting closer as a family, rather than looking for every thing to be wrong, you may find they start to take an interest in Islam and may start asking your son or you questions to learn more. However, if you keep pushing them away by constantly “telling” them what they can and cannot do, you will drive them away. That would be sad for everyone concerned, especially the children.
I would not limit the time the children spend with their grandparents, because the more time they spend with their grandchildren, the more they will come to learn of Islam and of a happy way of life insha’Allah. Your treatment and behavior towards them may be the only learning experience they have of Islam. Insha’Allah, make it a positive, loving and compassionate one sister.
You and your family are in our prayers, please let us know how you are doing.