When blessing others, the most important thing is sincere and heartfelt blessing. For the mutual blessing between aunt and sister-in-law, it is also to express the feelings of mutual concern and love. Although there is no blood relationship between aunt and sister-in-law, they also have a profound friendship of long-term coexistence and mutual support.
You can express your concern for your aunt's career, wish for their life, or give some spiritual encouragement and support.