Those of us who came of age in prehistoric times (AKA land-line only

) remember the difficulty of finding someone who had changed
offices 
. Only if a co-worker, still on the job, recognized you and knew your status, MIGHT you find out where she'd gone.
On the arrival of mobiles (SIMPLE mobiles, voice and sms), their value was quickly learned for the advantage of direct contacts

. Even if her English was MINIMAL, she could give an SMS to a (human) translator who would translate and then return an answer. Still, it was limited to sim cards (as in local), so you just might get a different voice when you called her number, she having sold the card, with her contacts, to a colleague on her departure.
With smart mobiles and apps, all that has changed. Now independent of sim cards. Still subject to account termination (either she closing account intentionally on departure

, or accidentally with a mobile being dropped in some body of water, usually a toilet

), but accounts do have a tendency to be kept, even business ones.
Point is, take advantage and ask for the contact. Easier to delete than having to pine wondering, "where, oh where, is..."
YMMV