Thank You Notes To Coworkers

My mother has received some gifts for my little newborn baby of his colleagues from his own that I have never heard or met. Is proper etiquette dictates that they should receive written thanks from me?

Yes, the label is that you must meet all the gifts given to you.
The note should be personal to the situation, but the length of the note is not necessary.
Since the gifts were sent to you through your mother, it can help its mention in the note and your mom also deliver the tickets to his colleagues.

Of course you do. These people do not know you and even took the time and spent their money to make a gift for your baby. They did this because of their relationship with your mother. Not only would it be rude not to send them a thank you note, it would be insulting and embarrassing to your mother.

Yes, you do, ask your mother and they are sending them.