Sounds like she is just trying for a discount after the wedding with very little basis for it so definitely a no no imo.
Personally I wouldnt give a discount for anything unless I was removing something substantial from the package or I had completely missed something substantial, not just that the bride didnt like my version of what she asked for, thats far too subjective.
Interesting conversation last night, I had a new enquiry originating from the place we worked last weekend (gutted because were already booked for her date at about a third of the price from one of our first bookings of last year) and the reason the bride had contacted me was because she had planned to use the same photographer that her sister had used the year before but his price had come in at more than she had exepected so she had asked if he could do anything about it. He responded by straight away knocking £700 off his price without removing anything from the package, she dropped him immediately because she felt his prices had no basis, he was just making them up and she felt like she was being ripped off.
With the package she wanted our prices wouldnt have been that different from his original price and she was happy to pay that when she felt she was getting value for money.
Giving discounts for little or no reason undermines your prices and your business.