The 23-year-old American needed extensive treatment on a recurring abdominal injury early in her semi-final against Kim Clijsters, but battled back to seal a 4-6, 6-3, 6-1 victory.
"If I'm not 100 per cent fit I'll still be out there," Venus told reporters. "I generally don't play with pain, but this is a Grand Slam and I just wanted to win."
"It's not as bad as before, anyway it doesn't stop me running and I can still hit my groundstrokes," added Venus, who said she does not expect her younger sister to go easy on her when they meet in the final for the second consecutive year on Saturday.
Venus said the injury, which first flared up against Amelie Mauresmo in Warsaw in April, had not bothered her in the earlier rounds of Wimbledon and took her completely by surprise.
"I felt pain out there and I just panicked," said the 2000 and 2001 champion. "I didn't know if I could play, if I could hit, I couldn't calm down. That more than the injury cost me the first set."
After a lengthy rain delay at the end of the first set, Venus came out in a much more positive frame of mind, playing some of her best tennis of the tournament to overwhelm the 20-year-old Belgian.
"When the rain came down my mum and Serena spoke to me in the locker room and helped me calm down," she admitted.
IN DENIAL
"Basically I had to accept what had happened. I didn't want to accept that I was going to have to play with pain, I was pretty much in denial, I just couldn't get through it.
"They at least helped me get my head straight. My mom just said 'if you're gonna play, play. If you not gonna play, you know, pull out. If you're gonna hurt it more pull out'.
"My other sisters were there chiming in. I was just trying to take it all in."
Providing the injury allows, Venus will start Saturday's match trying to halt a run of four consecutive Grand Slam final defeats at the hands of Serena.
Serena's victory this time last year was the second leg of her self-styled Serena Slam, all at the expense of her older sister.
Venus, though, insists she will treat their sixth meeting in Grand Slam finals just like any other match.
"I'm really concerned with who is over the other side of the net, I'm only concerned with if I'm messing up badly. The only thing that may worry me is I know I'm not playing well," she said.
