Plaster (?) fell off? Help ...

[1john]

Well it is kind of irrelevant to you but houses built with stone tend to have very uneven walls and you tend to have very deep areas of plaster in order to straighten them out a bit, this is where you normally see wooden lintels also, I had initially assumed by the depth of plaster missing and the colour of it that you had a stone house, sorry for any confusion I may have caused.

The batten idea above seems the best route to take

 

[roy c]

If your house is brick or stone it has to have a lintol over any openings ie. windows and doors. Where I live the majority of houses I work on are stone built. They have 16 to 20 inch thick walls, usually on the outside there will be a stone lintol or sometimes a metal one, being either an "H" girder or sometimes a bit of railway track. And the internal one (or 2 or 3) lintols should be wood or sometimes concrete. Now where you have drilled you should of hit a lintol. If you put a spirit level from the head of the window and put a pencil line on either side of the revel and then measure about 3" in and 3" up from the line then drill a hole with your masonary drill then put a 4" screw in the hole and screw it in slowly , if it is a wooden lintol you will soon feel it "bite "in to the wood. If it's not then it will just go no further in and just spin around. If that is the case then the lintol will be stone or concrete.

Hope you can understand this and it helps you. There is no reason that you shouldn't get a fixing in that position...
Looking again at the photos I think that you may of missed the lintol with your drill, move back to the left like I said above and you should get your fixing.