If these girls had no idea about bitcoin, their question should be "What is bitcoin" but since they opted for dollar and not getting curious to know about bitcoin, shows that they have some knowledge of bitcoin.
Perhaps, but I also admit that the reason may still be that although they knew what bitcoin was, they did not know how to handle it.
There is no elemental knowledge about what to do with it, how to get it, they dont even have a cryptocurrency wallet for this. Therefore, you need to sell it somewhere, but they also have no experience. Therefore, it turns out that there will be too many difficulties for them with bitcoin, which they did not want to deal with, but preferred to simply take cash.
This situation may be for most ordinary people who have heard something about bitcoin, but have never dealt with it. This all seems simple to us, because we have already figured it out, but for those who have not delved into this issue, it will already seem very complicated and possibly risky.