Despite breaking Denise Lewis' British heptathlon record in Gotzis last month with a total of 6,906 points to sit comfortably clear at the top of the world rankings, her high jump - generally one of her strongest events - was below par.
The 26-year-old managed just 1.85m in Gotzis, her only previous outdoor high jump in 2012, when her personal best set in 2007 is 1.95m and she has cleared 1.91m indoors this year.
The Sheffield athlete added: "I have changed the run-up in the high jump a little bit, just made a few little changes, but I am quite happy now. I think if I would have had a bad jump here then I probably would have been slightly worried about it, but to have jumped 1.89m feels a lot more comfortable than it did in Gotzis."
Ennis, with her Olympic selection assured, is due to compete in four events at the Alexander Stadium this weekend with the long jump and 200m to come on Sunday.
She is the favourite to land the Olympic heptathlon title in London, despite losing her indoor and outdoor world crowns over the past 10 months.
Ennis added: "This definitely helps (my confidence). Running against Tiffany and beating her and doing what I did in the high jump all helps toward the summer.
"I don't mind the expectation because it means I am doing something right and things are going well, so if that's how it's going to be then that's a good position to be in."