Vlookup/index/match + concatenation

Hello all,

I'm having trouble figuring out a specific formula. I want to do a VLOOKUP (or something similar) that matches a value in a table in a separate sheet, and returns a specific value, but the kicker is that it will concatenate the values if there are two or more different values matching the initial lookup value.

Please see the attached spreadsheet example. I would run the formula in B2 of the first tab, and it would reference the table in the second tab. This is much smaller scale example than what I intend on applying to. There could potentially be more than 2 matches for a specific family number.

Thanks in advance.