I have made many kits now, and only 2 of them had the starting S.G. reading that I wanted to see (a Cabernet and a Merlot).
The fruit varieties I have made are intended to be lower alcohol (or "mist" wines) in many cases, so I understand those are supposed to have lower initial S.G. readings, sometimes in the 1.065 range - but I dislike the way they turn out if they start out that low so I always increase those.
Two techniques I've used thus far to increase the S.G. (and thus the final ABV):
- add table sugar (this works just fine, but can backfire if you add too much; and, I am told that making a simple syrup is a better approach, or else buying specialty sugars such as corn sugar or dextrose)
- add half of the "F-pack" before fermentation (the f-pack is the flavor or backsweetening pack that usually accompanies fruit wine kits, and is typically a thick syrupy substance essentially made from highly concentrated grape and fruit sugars; using half up front also means less of the F-pack available for backsweetening after fermentation is complete, which is fine if you want a higher alcohol fruit wine with a milder level of sweetness in the end product).
For my fruit wine kits I use a combination of both of those steps and I've had wonderful success, with refreshing fruity wines coming in between 9.7% and 11% alcohol, acidity around 3.4%, and a nice touch of sweetness.
If you decide to add sugar, there are formulas for how much to add per gallon to adjust S.G. - look for some online calculators to make it easier. Always err on the side of adding less than you think you need versus too much, as too much sugar can actually halt fermentation, paradoxically creating almost a preservative effect.