Mrs Lee's sister Claire Croxall, who told Ennis about the name tribute on Twitter, said of her niece: "Her mum and dad were supposed to be at the athletics for Super Saturday and were gutted when Emily's waters broke early on Saturday morning as they knew they weren't going to be going after weeks of excitement leading up to it, but of course they were thrilled that their baby was arriving.
"Just 20 minutes after Beatrice Jessica was born at Bath Hospital, baby and daddy snuggled up just in time to see her namesake achieve her Olympic Gold. They may not have made it to the Olympics, but they have a little part of the Olympics to treasure forever."
She added: "Needless to say we are all huge Jessica Ennis fans in our family now!"
Ennis, 26, wrote a message to Mrs Croxall after learning of her niece's birth, telling her: "congratulations! That's so sweet :)."
Mr and Mrs Lee, both 30, had been "desperate" to travel to London from their home in Derry Hill, Wiltshire, to take their seats in the stadium - despite their first child having been due some days earlier, on July 31. When primary school teacher Mrs Lee went into labour, they gave the tickets to friends, who have now returned the stubs, with a programme from the day, so they can be framed for Beatrice Jessica.
Ennis, who also retweeted Mrs Croxall's message to all of her followers on Twitter, said on the networking site that life seems "surreal" after her win, with a dinner invitation from Jamie Oliver and even a mention on an episode of EastEnders.