I would put her into kid again, and then sowly dry her off - I did it last year by not stripping my girl out, just eased out a bit of milk so udder is not full. After about two weeks she dried off. It needs careful watching for the first few days, in case udder gets too tight, you can always take some milk out, even if it is more than twice a day.
I feed my BT milker almost adlib, she is fairly thin but no ribs showing. My feeding regime is quite complicated... at morning milking time: about 1/2kg of dairy nuts and half a scoop of oats, lunchtime a scoop of soaked sugarbeet shreds with garlic and caprivite (recommended amounts), again half a scoop of oats, another 1/2kgs of dairy nuts, plus some carrots. At evening milking the same as in the morning. All these quantities are approximate, I only weigh the feed for my GG's in the last 6 weeks of pregnancy because they seem to get pregnancy toxaemia quite easily.
For drying off I would reduce the dairy nuts by half the first week, then to very little in the second week, but still keep up the sugarbeet and also oats. She will need some protein etc for growing and to put on some condition. You could also use an "all round" type goat ration when she is dry.
You can still milk her for the first two months of her next pregnancy with no problems, then start to dry her off before her last 10 to 8 weeks.