Every other week

The expression "every other week" has recently provoked a heated discussion on a YouTube channel. I claimed that "every other week" cannot always be said to be synonymous with "every two weeks". If a given event happens "every two weeks", there certainly is a two-week period between two consecutive events. However, if an event happens "every other week", the period between two consecutive events is not necessarily two weeks long. In the clause "she went to visit her aunt every other week", how long is the period between two consecutive visits? I would say it depends on the day on which she chooses to visit her aunt in one of the weeks and the day she visits her aunt in the week after next. If she always visits her aunt on a Friday (week 1), skips the following Friday (week 2), and visits her aunt again on a Friday (week 3), then one can say that "she visits her aunt every other week" means the same as "she visits her aunt every two weeks". However, if she visits her aunt on random days, sometimes on a Friday, sometimes on a Monday, i.e., "she visits her aunt every other week" cannot mean the same as "she visits her aunt every two weeks". Any thoughts out there?