The birthday speech to mother-in-law marks the day as being special. So if she is having a party why not add to it giving one of our speeches? They tell her that she is a bonus to your family. They speak of her good influence and of how congenial she is. They talk of shared incidents and family gatherings. It’s easy if you choose one of our speeches.
Alternatively, you might like to settle upon paragraphs from the speeches in the pack that best describe her. Each birthday speech to mother-in-law has a different, specific toast. As a wonderful finale why not end with one of our light-hearted poems?