There certainly isn’t any etiquette that says someone must take the place of your mother at your wedding. When your sister married, your aunt may have thought she was supporting your sister and your father as it was so soon after your mother’s death. There is no need to include anyone else on the top table unless your father feels he would welcome some moral support.
Leaving a space at the table may not be appropriate. Firstly, it means leaving a gap between two people on the table, and it could be rather upsetting for you and your family to have an empty chair.
There are plenty of ways to remember your mother on the day
– Choose her favourite hymn or poem and add a line to your Order of Service explaining your choice.
– Choose her favourite flower as your buttonholes or the centrepiece of the bride’s bouquet. Add a note with your invitations or information pack that says something like:
To keep Sarah close to our hearts, we ask our guests to bring/wear yellow gerberas/sunflowers/white roses that were so adored by her.
– Light a candle during the ceremony and dedicate it to her. Or, ask each member of the family to stand in front of the altar, light a separate candle from the church’s eternity candle and hold it whilst the minister offers a short blessing or prayer. Ask your minister or celebrant for advice.
– Take a collection for her favourite charity. You could even pass round small envelopes with her name on explaining why you want a collection for this particular charity.
– Ask the vicar to mention her.
– At the reception, stick a photograph of your mum into a little comments book and ask friends and family to write their funniest/most heart-warming/happiest memories of her. Ask the best man to read out a couple of the best stories in his speech.
– Leave a decorated box by the exit from the reception. Ask guests to leave their buttonholes there to take to the cemetery or grave at a later date.
– Ask someone to propose a toast on her behalf.
– Don’t be afraid to mention her name during the speeches or to include what you think she would have said had she been with you.
– Include her favourite food or recipe on your menu alongside a note explaining your choice eg. “No visitor to the Smith household escaped for long without tasting Sarah’s indulgent chocolate brownies so we wanted to continue that tradition and ruin the diet of many of our wedding guests.” Offer her favourite apperitif or name a cocktail after her as an alternative reception drink.
– Pick the same first dance as your parents and ask the toastmaster, bandleader or DJ to explain your choice.