The meeting the voice at Makers End mentioned was NOT the meeting at november 3th, 2064. Faro and Sobek had a lot of meetings after that date and not all of them took place in the Zero Dawn Facility. The computer at Makers End was simply not updated when the FAS-facility was abandoned in the end of 2065 or early 2066, because there was no time and no need.
Let's talk about Aloys Age: We know that Gaia created her in the event of her own self destruction on august 26th, 3020 at 8:45 AM. Aloy was "conceived" the same day at 12:08 and born on april 4th, 3021 at 9:30 AM (see the datapoints "Chamber B1-001" and "Operations log" in Eleuthia-9 ). That means, the artificial pregnancy lasted only a bit more than seven months.
Another important information is, that GaiaPrime exploded "20 years ago" (Sylens mentioned it, I think). And that means - if it really happened exactly 20 years ago - Aloy is around 19 years old (20 years - 7 months), and the events of horizon zero dawn occour in 3040.
But at this point we do not know her exact age and the exact current date, because the informations about the explosion are limited to "20 years ago".
And that redirects the overdue meeting to (3040 - 972,7 = ) the year 2067. But this makes no sense, because it was a well known fact for Sobek and Faro that humanity would not last this long. So it looks like Sylens was not very precise in counting, when he said "20 years ago" and rounded up to the next full decade, because it was almost 20 years ago.
So it makes more sense to place the overdue meeting in early 2066 and then we are (2066 + 972,7 = ) in 3039. 3039 - 3021 = 18
So it looks like Aloy is in her early 18th. But again, there is a little uncertainty of several months, because we do not know the exact date of the meeting between Sobeck and Faro and because of that, we do not know the exact "present date"...
