The 29-year-old produced her three best performances since the Olympics at the weekend's Anniversary Games in London.
Ennis-Hill and coach Toni Minichiello are set to make a decision by Monday, with the British team named on 28 July.
"He's kind of been up and down," said Ennis-Hill. "It's going to be an interesting conversation."
Ennis-Hill, who only returned to competition in May following the birth of her son Reggie, impressed in the 100m hurdles on Friday before setting season's bests in the long jump and 200m on Saturday.
"I am making progress and my times are coming down. I'm really happy with this weekend," she added.
"The training I've done over the past few weeks has made a big difference."
But the Sheffield athlete said she would only compete in China if she felt she could challenge for a medal, with defending her Olympic title in Rio next summer the key target.
"This weekend has given me a good indication of where my speed is, but I've got to make sure that my other events are going well.
"I'm towards the end of my career. I've had an amazing career already and achieved so much. Rio is the main thing for me and I want that to go the right way.
"The World Championships this year was always going to be a massive bonus."
Katarina Johnson-Thompson, one of Ennis-Hill's main rivals, was down on her best in the long jump on Saturday, but said she had been hampered by a quad problem for the past three weeks.
The Liverpool athlete said: "Considering the preparation I've had for it I'm over the moon.
"I was worried about it before this competition but now I'm completely fine," the 22-year-old said.
This was the first time Ennis-Hill and Johnson-Thompson had gone head to head since the former's return to the sport, and her younger rival urged her to go to Beijing.
"I said to her she has to do it now considering what she did yesterday and today in the long jump, so I'm sure she'll be there," said Johnson-Thompson.
Olympic heptathlon champion Jessica Ennis-Hill says she is still not certain to go to the World Athletics Championships in Beijing next month.