NikiTaylor's fame and fortune has been marred by a terrible family tragedy that haunts her every single day: the heartbreaking death of her kid sister.

 Krissy Taylor was a promising model following in her big sister's footsteps when she died of an asthma attack in 1995. 

 Nikifound her sister's lifeless body sprawled on the floor of their family home in Pembroke Pines, Fla. 

She launched a desperate attempt to revive Krissy, pumping on her chest and breathing into her mouth - but the efforts proved futile. 

An autopsy revealed the sexy, 17-year-old brunette had died from complications of asthma. 

Friends later said that behind Krissy's warm smile was an intense fear that she could suffer a nightmarish asthma attack at any time. 

It also was revealed that Krissy carried an asthma inhaler and prescription painkillers everywhere she went. 

The sisters had been extremely close and had even posed together for top fashion magazines. 

"It made Niki realize that life is precious - that it can be gone in a flash," one family friend said. 

 Niki managed to push some of her grief aside when she gave birth six years ago to twin boys, Jake and Hunter, with her husband, Arena Football star Matt Martinez. 

"My boys are the most important thing in my life. I love them so much," she gushed. 

But within a year, she and Martinez divorced.