yep, all guttering needs to be checked. When it next pours with rain, if you can get over there and see if any water is pouring down wall, that’ll give you a clue.
Also, are the windowsills sandstone? These are very typical on victorian houses. Eventually, they become permeable and allow water into the brickwork. Because of this issue, I had to strip all the sills back on one of my rentals, apply a water barrier sealant and then three coats of some heavy duty external paint over the top. This was on top of dealing with water penetration all along the interior of the 1st floor external wall in two rooms. It’s done the trick though.