Wore a bikini even though my sister had given birth

My parents, my older sister Jeena (33), her husband George (30), and their son (1), as well as my husband and our daughter (2), we decided to visit a beach club for the first time during our family summer vacation. 

Jeena had approached me beforehand, asking if I could avoid wearing a bikini or anything revealing during our time at the beach club. She explained that both she and George were feeling a bit self-conscious about her postpartum body, and she wanted to avoid any uncomfortable discussions about it. In response, I expressed sympathy for her feelings but shared my intention to fully enjoy the beach by swimming and soaking up the sun without being overly covered up. I pointed out that many other women would likely be wearing bikinis, so I didn't believe my choice of swimwear would be a big issue.

On the day of our beach club visit, she appeared visibly upset and anxious throughout the day. Unfortunately, her discomfort continued into the following day, leading her to decline joining us at the beach once again.

My parents have now weighed in on the situation, expressing their concern that I should have been more considerate by wearing a cover-up that still allowed for swimming. They've also mentioned that my refusal to do so could potentially negatively impact the overall enjoyment of the vacation.

Despite her request, I chose to wear regular swimwear for comfort and enjoyment. This decision seemed to upset her and has now led to tension within our family vacation. My parents believe that my choice could have been more accommodating, potentially preventing any disruption to the vacation experience.

Now that I have realised, it was George who had pointed out her postpartum body and had declined her to wear it so that he doesn't feel ashamed. That's the red flag that she should be concerned about and not what her sister is wearing at the beach. Was I wrong here?