Why would she be collecting phone numbers? Like for what purpose?
Worst case scenario - if you didn't have a designated punting phone, your mobile number could be a relatively easy way to find out who your friends and contacts are and use it for blackmail/threats/outing to friends and family (please note I am not accusing this lady of this, but we only have to look at the UKP Blacklist to know it happens). Someone collecting numbers for a scam might only need one legitimate 'non-punting phone' number to enable them to start blackmailing that person for cash.
In this case, something felt wrong because the email I gave her works fine (It is the one linked to my AW account and nothing else, and the notifications from AW come through fine) so there was no reason not to use that. Plus, as I said earlier in the thread, I was not convinced the group she is a part of is OK. I was probably being paranoid, but in this business, I take the view that it's better to be cautious if something doesn't feel right, however small.