Well, Engebrecht is pretty much the same as Engelbrekt, isn't it?
What's uncommon is rather that 'e' and 'n' are more or less indistinguishable in that hand.
Ingeborg starting to have children at eleven does seem like the wrong rabbit hole, though.
I also wonder if Engelbrekt Larsson's Ingeborg, born 1711, is the same Ingeborg as "pigan Ingeborg" in his household in 1720. She ought to be "dottren". There aren't any sons or daughters on Engelbrekt's page, but the households on the previous page have several.