It is Virgin's responsibility to "make you whole". Whether that is finding the stroller and delivering it to you, or covering the cost of a rental in the meantime, or covering the cost of a replacement, they have a department for that. Here's the link with everything you need to know:
VIRGIN MISSING BAGGAGE.
Call them, and keep on them. It wasn't Virgin, but we flew British Airways to London for a cruise in late May. My husband's bag did not make the connection and was left in Chicago. (Mine made it, go figure.) We filed the case with BA at Heathrow (did you do that with Virgin?), and they told us they would deliver it to us at our hotel the next day, and we should purchase essentials in the meantime, saving our receipts to file a claim. Well, the bag did not make it to us the next day, or the day after in Southampton, where we were boarding our ship. I talked to them a couple times a day trying to get this resolved, and when it was apparent that we would not have the bag for the cruise, they said to buy what we needed. We had a fun shopping day at Marks & Spencer, Decathlon Sports, and Boots, and my husband soon had everything he needed.
In the end, the bag was returned when we arrived home 10 days later. We scanned all the receipts, filed them online, and two days later had a direct deposit from British Airways into our checking account for about $800, the total value of our receipts.
Long story, but airlines are required to take care of passengers whose luggage they lose.
And I agree with the previous poster -- you have this huge trip overseas and do not have any contingency plan for something going awry? No credit card? That seems dangerous, to me.