Hi E.,
Our babies were born in February, also! (Boy/Girl twins.) I don't know much about the stages of jarred baby foods, because I'm making our baby food (if you're curious, a great book is "Super Baby Food"), it's easier than you might think! (and it's SO much cheaper!!! I can get 28 servings out of a bag of frozen peas ($1.59), and save about $14.00!!) The book lists what they can & can't have each month. I've been going easy on the spices and putting their food in the blender, then pouring the extra into ice cube trays and freezing it for future meals. The vegetables are really easy, I just prep (or use a bag of frozen) and microwave them til they're soft, then puree with a hand (stick) mixer or in the blender. For foods with protein, I've made chicken soup, brown rice with lentils and carrots, or sometimes I just mash tofu into their veggies. They also say the babies can have egg yolk, but no egg whites, so I've made boiled eggs and mashed them up a bit for finger food...was really quite dry, though :P. The food that they love to pick up and eat themselves are cheerios or zweiback toasts. Tried plain pasta the other day, it got stuck in my son's throat and made him gag...will probably try a different shape next time ! :)
I go easy on the juices, just diluted apple, white grape or pear; but a the first sign of bumps on their bottoms I go to just water for a day or so. (these bottled juices also have ascorbic acid in them, but I guess just less than orange or grapefruit? who knows?) Haven't tried any tomato sauce yet, my daughter has really sensitive skin, so I'm going to wait until they're a year or so. I know other moms who have given it at this age without any problems.
I would give a little bit, then wait a couple of days to see what happens...if there are no bumps or signs that it was a bad idea, then go with it.
Hope this helps...let me know how it goes! Does Alexis have any teeth yet? Is she scooting around? Cassidy is all over the place, but Andrew is still just doing the log-roll thing. It's wild to see the differences between boys and girls. She babbles away while he hangs out and listens!