Star Fruit Mead

I used about 7 lbs. of wild flower honey and 1 gallon of star fruit puree to make a 5 gallon batch of melomel. I pitched Wyeast Sweet Mead with 2 tsp each of yeast nutrient, yeast energizer, and yeast acid blend.

My OG was 1.052 when I racked to primary on 9/28. I racked to secondary on 10/4. My specific gravity is now 1.003. I am fermenting this at about 76-78F degrees. I calculate my ABV to be about 6.5%. I expected about double that.

I am looking for help in trouble shooting. This is my first mead batch. Has it locked up? It tastes like a cider. Good flavor. And I assume that it will mellow out a lot in bottle fermentation. But it seems odd that it is so low in ABV. Not a bad thing altogether, but not what I expected...

I don't think star fruit has as much sugar as you think it does. You did not describe how you prepared the star apples, usually cutting up and kind of mashing them, then freezing them in bags to get the ice crystals to break up the cell walls is the easiest way.
Even then 1 lb is only going to provide a few points on the SG for 5 gallons and your primary source of sugar would be the honey.
At 7 lbs your very light at 1.4 lbs/gal. Per hightest's spread sheet these are the normal ranges.
Dry: 2.5 - 3.2 lbs/gal
Sweet: 3.4 - 4.0 lbs/gal
Sack: 4.3 - 5.0 lbs/gal

On the bright side, it will be ready to drink much faster as there are fewer esters to age out.
I hope this helps, I would really recommend reading through the sticky FAQ at the top of this section, it made me realize how little I really knew about meads and yeast.

Thank you. That was a lot of help and made things a bit more clear.