She followed that up by competing in the long jump and 100m hurdles at the weekend event in London, which commemorated the one-year anniversary of the Games.
The 26-year-old said on Saturday that she was not sure she would be fit in time
But Black was more optimistic, telling
BBC Radio 4's Today programme:
"It was incredible to see her coming back and competing at Loughborough through the week then seeing her hurdle and long jump.
Johnson-Thompson wins long jump
"The team around her, led by coach Toni Minichiello, have done phenomenal work."
On Saturday, Ennis clocked 13.08 seconds in her first hurdles race since London 2012 - more than half a second slower than she ran at the Olympics - and confirmed afterwards she had only started hurdling again in training last week.
The 2009 world champion then came eighth and last in the long jump with a best of 6.16m, behind compatriot Katarina Johnson-Thompson who won with 6.46m.
"It's amazing to be back in the stadium and just having everyone's support is incredible," said Ennis-Hill. "I'm just disappointed that I'm not in the shape and the fitness that I need to be in.
"It's hard because obviously it's only a couple of weeks until the Worlds. I'm running out of time a bit."
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