There you go, getting all pedantic, and not reading it correctly. Please read the requirement again, a TOTAL of 100nm. So 51nm out and 51nm back does the trick.
By the way this is an accompanied flight, not solo, and if you do it right you can knock off many if not all of your night landing requirements at the same time.
The 100nm mile part comes probably from the old requirement for the long cross country (day VFR) that used to require a 300nm total distance with one leg at least 100nm long. This is no longer the case.
Regards,
White Bear.