Is there such as thing as a last minute deal on Eurostar?

[Goodluckcharlielover]

Thinking of taking my sister (over from States) if can find cheap enough deal - just a couple of days

No I don't think so, unless you can get a deal with accommodation and travel together. Eurostar itself has the cheapest tickets available 3mths before travel and they only have a certain no at the cheapest price, so best to time when you book if possible.