Now that we've got more definitive ages between PCs and important NPCs here's a list
teor and kattigan: mid-to-late 40s
thjazi, cyd pridesire: mid 40s. thjazi was 44-45 when he died. cyd is two years younger than teor.
murray: minimum of 40 but she's only said definitively that she's younger than bolaire (so basically anywhere from 40-65). probably mid/late 40s.
thimble: 30s at the youngest. she tells wick she's older than him and she was thaz's sidekick for 19 years (though she's only been aging like a mortal for 8 years so she still looks very young & her chronological age and emotional age are a little different due to her magical nature)
wicander, azune, alogar fang: 27
tyranny: 6 months in a physical body but older than time
obviously there's a chance some numbers could get more exact.
we also have several NPCs with no exact ages but a general vibe:
callowyn royce was likely in his late 30s/early 40s
yanessa halovar was "a young girl" at the end of the shaper's war when the celestials went mad, so she's probably 75-80
godard & iris are mid 50s, judging by kids ages. filoneus likely late 40s/early 50s
zebani halovar is at least a year older than wick, so anywhere from 28-30. their younger brother probably no older than 26
primus is a minimum of early 60s due to petra and ryah's age, but more than likely a little older than that, so maybe ~65-70
segundus and trimus are likely in their 50s at the youngest
petra and ryah are late 30s/maybe as old as 40
ethrand is likely around 23-25, frons likely around 25-28 (close enough in age occtis knew him)
tertia was 18. univere is likely mid-to-late 20s & doset in his mid-20s, as he was old enough to get married a couple of years prior to campaign.
loza blade is younger than the shaper's war but being roasted for being old, so maybe 65ish
augustus valian is early 50s
amariya cormoray was middle aged, so late 40s/early 50s
otto einfasen is likely in his late fifties or early 60s, with harondus in his 30s
