Putting together a wedding today has costs not seen for sometime. A nationwide study shows that the average cost for the bridesmaid can run over $6,000 as the breakdown can be found here in the link below:
It is obvious to me that by reading the accounts of what has been said that the bride's mother is controlling much of what is being done here in this wedding. Before your daughter decides to think otherwise of dropping out of this event, have her speak to the bride privately and see if something can be done to tone down the costs that are adding up. The other bridesmaids I am sure are having the same problem so also have them talk with the bride to see if costs can be lowered. Hopefully the entire bridesmaid group can get mom to lessen the load for all.
If nothing can be done to lower costs, then it would be up to your daughter to see if she wishes to continue. I would bet though that the bride herself will do whatever she can to keep everyone happy in her party so lowering costs could be something she will do.
Sorry as typo on costs as it should be around $1,600 total cost for the bridesmaid.
I hope that my thoughts on this matter can help in giving some idea to your daughter to have the costs lowered for all to enjoy the event. If you could take a moment to rate my assistance so that I know my help was useful as well as allow me to assist others such as yourself.