Oh they are adorable!! The babes are so precious. Likely 4 weeks old. Can you weigh them? 40-50 grams would put them at 4-5 weeks old. You can also feed them baby cereal. I cook Cream of Wheat with a bit of brown sugar and butter for calories. You can also give them peas (I use frozen, thaw in warm water before I feed) It's one of the first solid foods they can hold onto. Make sure they are drinking from the bottle. You should also put a small bowl of water in for them, give them a choice of where to get their water. That's why the jarred baby food is good, lots of moisture. Good luck with your darlings 💞
Also, are they both boys or both girls?