I'm a bridesmaid in my brother's destination wedding, which is going to be a lavish, very expensive affair. His fiance's mother is throwing a large shower in a few months (I know this is a huge breach of etiquette, but there's no stopping them at this point; my mother was actually asked to co-host, and she politely declined). I live across the country, and will have just started a new job when the shower occurs; it will be both very expensive and nearly impossible to attend the shower, given its date and work commitments/conflicts. Is it impolite for me to send my regrets and a gift? When my future sister-in-law invited me to be in the wedding party, I warned her that my job/distance would make it difficut for me to participate in all of the pre-wedding activities, and she told me not to worry about it. She's already became upset that my mother declined to host, though, and I don't want to do anything to worsen the situation.
You are fine. And, please don't feel that your gift needs to be expensive. You could join with the other attendants in a group gift or give something inexpensive.