This might actually be a way of doing things for a woman going into her second marriage. She is having her mother escort her from her hotel to Windsor Castle where Doria will go ahead and take her place in the congregation. Meghan, along with her little bridesmaids and page boys will enter the Chapel and proceed up the aisle to the quire as a single woman, on her own and freely coming into this marriage. She meets Charles at this point where he, as a representative of the House of Windsor and father of the groom welcomes her and escorts her towards his son whom *he* is giving in marriage to Meghan as its his son's first marriage and has the blessing of his family.
I think its a touching and symbolic way to work everything of importance into this ceremony. I'm sure that if the Archbishop of Canterbury and the Church of England had any objections to the way this is being done, it wouldn't be done this way at all and quashed right quick. It takes into account that this is Meghan's second marriage and that no one is "giving her away" but yet brings a ceremony into the 21st century where the father of the groom is also playing an important part in this union.
I absolutely love it.