|Who may host a shower?
Traditionally the Maid of Honor (either on her own or with the help of the other bridesmaids) will throw a shower for the bride. Other likely candidates for hosting a shower may include close friends of the bride or groom, co-workers, or relatives of either the bride or groom. Most anyone that knows the bride and wishes to throw her a shower may do so. There is of course that age-old etiquette "rule" which still states that the bride's mother, sisters and grandmother should refrain from hosting a shower for the bride. According to traditional etiquette this may look as though the bride's family only has one motive—to collect gifts for the bride. Though, we would also like to point out that in certain areas of the country it is traditional (and expected) for the immediate family members of the bride to host her a shower. If this is the case in your community, ignore the etiquette rule mentioned above.
On another note, even though the mother of the bride and the bride's sisters do not traditionally host a shower for the bride, they may certainly offer their home (if they wish) for the shower's location. They may also offer their help to the hostess if they so choose.
When the shower is going to be a co-ed event, the Best Man and/or groomsmen may throw a shower, as well as any of those mentioned above. There really aren't any strict rules here.