A mother gives your life but a mother in law gives you her life. If your mother-in-law understands you well and it helps you to get comfortable in the new family then you should always be thankful to her.
Dear mother in law
I want to thank you for not only the reason that you actually raised such an amazing son but also for you taking this awesome decision of actually making him the most important part of my life as my husband. You always understood us and cooperated with us in all the ways you can. It is my pleasure to be a part of a family and I am so thankful to you for the wonderful vacation which you gave us. It was a real fun out there and yes obviously we missed you all.
You deserve all the credits for making my life so beautiful and wonderful with your son. I heartily appreciate you and applaud you for being the most wonderful mother in law. The weather was awesome and we really enjoyed it a lot. there was a lot of stuff to explore and we also did different adventures. Thank you so much for such a beautiful vacation which we got on our honeymoon. I will never forget this trip and this made a special place for you in my heart.
I hope everyone around me will be as wonderful as mine in law. I am so blessed to have you all. Thank you for making this bond deeper day by day.