After marriage, their relationship could evolve in a way that they become more of a political power couple. They would use their combined influence to make positive changes in the Sand Village. Emotionally, Gaara would start to show his softer side more often, especially when they are alone. Temari would be the one to encourage him to relax and enjoy life outside of his duties. They might also have arguments from time to time, like any couple, but these would only serve to strengthen their relationship in the long run as they learn to understand each other's perspectives better. And perhaps they would start new traditions in the village related to their marriage, something that would symbolize their unity and love for the people.
After marriage, their relationship might develop in a very supportive way. Gaara, being the Kazekage, would have a lot on his plate. Temari would be there to offer her advice and strength. They could also start training together more often, sharing their combat techniques and becoming an even more powerful duo. Their love could grow deeper as they face the challenges of ruling the village side by side.
Their relationship could develop in terms of them learning more about each other on a personal level. Gaara, who has had a difficult past, might open up more to Temari about his childhood traumas. Temari, in turn, could share her dreams and hopes for the future. They might also start a family, and the experience of raising children together would bring them closer. Gaara would be a very protective father, and Temari would be a loving and strict mother. This new chapter in their lives would be filled with growth and discovery for both of them. In addition, they could also start diplomatic missions together, representing their village and strengthening their bond through shared experiences in the outside world.