1. It appears that your wife and her parents are immature in domestic life,
2. Within 8 months of marriage, when your wife is pregnant, you should have been in seventh cloud and not thinking any thing about divorce,
3. I shall suggest you to bear for some more time till she delivers,
4. Her priorities may change after child birth,
5. Any warning to your wife or parents may aggravate the situation and lead to actual divorce,
6. Please note that divorce is the 2nd most stressful event in one's life,
7. If things become beyond your tolerance, you may inform youe parents in law to stay away from your family life otherwise you may consider divorce to get rid of them. However, it should be the last step.