A lot of our family have the same middle name. My mums middle name is Maree, her cousin's middle name is Maree, both the cousins daughters have the middle name Maree, and my DD3 will have the middle name
Maree. Same as Rose- we have several family members with the middle name Rose.
The only thing we don't do is use the same first name (For example I like the name Jack but wouldn't use it be cause my cousins little boy is jack). Unless its a father naming his son (so DH naming our son Michael).