Yeah that’s what I’m thinking also, he is same breed ND he’s small tho. Yes, I got a little kit put together for when it happens.Certainly sooner than April since a goat's gestation is only 5 months 5 days and this is September.
What size is the buck you think she was bred to? His size will be the important thing in ease of birth. While singles are good as far as her ability to produce enough milk for them is concerned, twins would be smaller than a single large kid and easier to pass through the birth canal. On the other hand, given her small size, possible lack of nutrition when breeding, and as a FF, she may have only one. This is fine since you are only concerned about a safe birth.
Don't increase her rations since you want the kid to remain small for an easier and safer birth. You can increase her feed with some grain after the kid is born and she is milking. Read up on instructions for pulling kids in case you have to help her get it out. Buy some antibacterial liquid soap to use as lubrication fluid if you have to go in and untangle or pull the kid. There is better stuff available commercially but depending on your location and what is available locally the antibacterial liquid soap will work fine. Have dry towels ready since when pulling you use them for traction on the slimy, slippery kid.
Don't stress, what will happen will happen. Odds are that she will deliver a small kid just fine on her own. I find that being prepared for the worst almost always means the worst doesn't happen. Good luck.