I had mixed feelings about this idea. Certainly it’s a striking email to read:

I have a tallit of my late husband’s that I wish to pass on to my son. My husband was a man of very small stature and, as a result, had a relatively small tallit. I was wondering if their was a ways to insert this tallit into one of a more appropriate size for my son in order to honor the memory of my husband.
Thanks in advance for your help,
Debra K.

I told Debra her intentions are admirable, but it’s not feasible to make a tallit bigger.

If he had a tallit bag, there’s a good chance it will fit a larger tallit, and if so, she could even have both of their names embroidered on, e.g. Yosef ben Shlomo, etc.

Or if the atara (neckband) is in good condition, she could easily unstitch it and sew it onto a new tallit.

But there are two reasons her original idea rubs me wrong. One is that a tallit is essentially a garment. Most son’s would feel uncomfortable wearing their dead father’s suit or shirt. (The Gemara specifically prohibits wearing a dead person’s shoes.) The other reason is that an old tallit is often yellowing and shabby. We are enjoined to do mitzvahs in an aesthetically pleasing manner. I often see people wearing old tallits, apparently because they hold sentimental value or because some people think a worn, antique look makes a tallit more distinguished.

In my opinion, having a nice, new tallit overrides those inclinations and is a bigger mitzvah.