When I was researching this for my blog, I couldn't find any LEGAL requirement to seat parents with their children (as surprising as that might be). It's simply down to each airline's policy and VS' isn't great. https://help.virginatlantic.com/gb/e...-children.html

Do OLCI as soon as it opens, and you should get the bulkhead seats (reserved for baby bassinets). Otherwise you will indeed have to juggle with others. (ask a flight attendant) As annoyed as they might be, sitting next to an unattended 4 year old is even lower on anybody's list of fun things to do on a plane.