What OS for early 2011 MacBook?

Hey guys,

got an old MacBook for my gf at a super cheap price - because her current windows Lenovo is torture level slow

Heard OpenCore allows me to put a newer OS on the MacBook just to make it feel a bit less like a relic.

Wondering what OS is recommended for the spec of this early 2011 MacBook.

Here’s the spec: - she is not super demanding for her tech - just uses zoom/ notion/ basic software - doesn’t need any heavy processing work - she wants to to get into the Mac ecosystem for when she has money for a newer model - this would be a great, cheaper MacOS entry to replace the Lenovo horror

Here’s the girlfriend: - 13 inch, early 2011 - 2,7 GHz Intel Core i7 - 8 GB 1333 MHz DDR3 - Macintosh HD - Intel HD graphics 3000 512Mb - currently running MacOS Sierra V 10.12.6

I understand that I obviously can’t put OS Sonoma on a 2011 device, especially because this one is not maxed out with higher ram/ ssd

So open for recommendations. Thank you!

PS yes I did research this sub but every answer seems to be about fully specced/ maxxed MacBooks. This one is mostly stock.