You can discuss that. Talk about how sad she was after your dad died. What did you notice about her? Did she used to sing in the kitchen? Did she love to dance but hadn’t danced in years?
Talk about the qualities you missed.
Talk about how you knew it was love. Why? What did your mom do to show you how happy she was? Talk about how happy you are that someone will be there to take care of her for the rest of her life.
Talk about her smile, how he treats her, things they do together. Don’t think of it as writing a speech but think of it as talking to a friend.
