In the first two paragraphs, what evidence shows that others perceive Mrs. Mallard as weak and fragile?

The first two paragraphs of Kate Chopin's "Story of an Hour" make it clear that Josephine and Richard perceive their sister and friend as weak and fragile. First of all, it is apparently well-known that Louise has heart trouble; thus the others make it a point to be careful about what they say and do around her.  

Josephine, then, must break the news of Louise's husband's death carefully, "...in broken sentences; veiled hints that revealed in half concealing" instead of in a more forthright manner. Richard, too, takes the extra time to double-check the list of passengers in the trainwreck before he hurries to give the news to Louise. He "had hastened to forestall any less careful, less tender friend in bearing the sad message" because he was afraid that the shock of the news might affect her heart.

Ironically, Louise is not as upset as they think she is. However, her heart is still weak, and suddenly finding out her husband is alive make Richard and Josephine's fears come true.