The most likely scenario that I can think of is that the church did fundraising under another name, perhaps as part of some particular campaign, or they had other people doing fundraising for them.
For example, a bank chain here in the NW is accepting donations for Haiti Relief. Those donations are actually going to the Red Cross, and any giving statement would come from the Red Cross. The bank is just a middleman, but people may not remember that a year later.
Another scenario is that your wife bought something and part of the purchase was considered a donation. This happens all the time with church auctions or rummage sales. PBS does it with the promo packages they sell during fundraisers.
Did she recently give money to a memorial fund for a deceased person? I ended up on the mailing list for an animal shelter in Florida that way (I’m in Wisconsin). I e-mailed them and told them I wanted off their list and why, and they gladly took me off the list.