at first I want to protest LOUDLY against this newspaper that qualifies 43 year old women as "old"!
Second, I had a similar situation in Brussels one year ago. Brussels also is normally a very peaceful place, and I also never had fear of walking or cycling alone wherever at whatever time.
But then, I was in the metro, around midnight, going home and reading a German newspaper (der SPIEGEL). The metro was not empty, but there were not very many fellow travellers. A group of German tourists, all male, all in their teens, and all already in a very hooligan mood, entered the metro. They were singing and shouting loudly, and took places in front of me. I think they recognised the German paper and saw I was German, and they started to sing primitive, sexist songs of the worst type (if you translate into English, something like "Women are a ware to share, open your trousers, get aroused, lets share some broads"). There were around 15 of them, all Belgian passengers happily ignored them, and I tried to do the same...If it had been one, two or maybe three persons I'm sure I'd have said something to them, hoping that if they get aggressive I'd defend myself and some other passengers might interfere, but against 15 macho idiots?
I do not think that randori would help anything against 15 aggressive persons, even for a much more advanced aikidoka. But I think what makes a great difference is if aggressive people see that you are scared. It's like dogs, you show your fear and they feel compelled to attack. I have the great advantage of reacting slowly, and before I understand that a situation might be dangerous it's normally over, but I think for more sensitive people this might really be a more important point than knowing randori techniques.
To resume, what would I do?
1) Outwardly, trying to be very unconcerned and not at all afraid, maybe saying something cool if ever I had a good idea (probably not)
2) Inwardly, pray very fervently