Venus Williams has always taken her role as big sister to Serena very seriously but never before had she thought a bit of family intuition would end up saving the life of the 13-times grand slam champion.
Serena, who once starred in the American medical drama ER, found herself in the centre of her own health scare in February when she had to undergo emergency treatment after a life-threatening blood clot was found in one of her lungs.
Had it not been for a tip off from Venus, Serena may have been prevented from making her long-awaited comeback to competitive tennis this week in the Wimbledon warm-up tournament in Eastbourne.
"I remember I was in the gym and Serena called me and said 'my foot's swelling'," Venus, who is celebrating her 31st birthday this week as she too makes a comeback, said."My physio and I were both there and I said 'you need to look up online on symptoms of blood clots'. So she did and our physio went back and what do you know, it was. "She had lot of the symptoms and thank god she did not ignore it because that could have been dangerous.
"I wasn't with her so it wasn't like I could do anything... but I just suggested because it was one of the symptoms. I did not believe this could even happen to her."
A tennis champion, fashion designer and interior designer, Venus never thought her limited medical knowhow could prove so crucial. "Someone like Serena, who's a champion and a legend and has spent her whole career and lifestyle being healthy, it's hard to expect her to have a health problem like she did," added five-times Wimbledon champion Venus.