While it's always best to have your name on your ticket match your national ID in every particular, I suspect this won't be an issue..
I would call BA before travel and see if it can be corrected.. some airlines can or will do this in cased where there is a compelling case of 'clerical error' in the name.. not all do, but some will.. if BA says no or wants to charge you (which any changes to a ticket does commonly trigger a fee) then I'd ask them to "note" this issue on your reservation-- formally called your PNR or Passenger Name Record.
That way, if, on the off-chance you're asked about it at check-in, you can explain what the matter is and that you did attempt to correct it..
Lastly, if BA made the error then I'd expect them to fix it.. but commonly you need to point this out to them ASAP once you get your confirmation and not days/weeks later.. same general thinking if it was an agent..
If *you* made the error, then unfortunately, you're kind of at the mercy of the airline.. I will say that odds it will be made an issue of are less than 10%, but again, by rights a person named Sharron is in fact different that Sharon.