Guests addressing their own thank you cards

Melissa 4637

I saw the recent post that mentioned asking guests to address their own thank you cards.  My mother-in-law did this for my wedding shower and she just asked me to provide her with the envelopes so she can do it again at my baby shower next month.  I thought it was kind of tacky, but now that I see that other people agree, what should I do?  It is a small, family shower, and everyone there has done it before for me or my sister in law.  Should I ask her for the addresses and tell her I will address them myself, or just go along with her plan?  TIA!