John Grubb
Had business at the hospital today so went around for a look-see. The "sign over the door" does indeed just have "Tops Day Nurseries" in a stylised font with the company logo on it. I'm inclined to think the name on the map should be the same as the name on the sign, as per OSM Wiki. I mean, we don't label chain shops individually on the map, do we? - e.g. WH Smith is tagged "name=WH Smith" wherever it is mapped and not, say, "name=WH Smith (Taunton)" or "name=WH Smith (Exeter)."

I'm of the view, then, to revert to "name=Tops Day Nurseries" but will await a consensus of other more-seasoned mappers for a short time.