as for the size pot, i would get a pot that stands at least3-4 inches taller than the one she is in now. then let her soil dry. fill new pot 1/4 way with new soil. since you have so many nutes in their, just use plain potting mix. anyway, hollow out the center of the soil in the new pot until you have about 1 inch layer on bottom and sides. put 1 hand very gently across dried soil looping your thumb and forefinger very loosly and gently around the stem base. very gently tip the pot over sides ways, positioning plant above the new pot, and lightly wiggle old pot very gently until it loosens and you can pull it off. pull it off slowly so you can look to besure that roots are staying intack. if they feel like they are stuck, then replace plant. otherwise place plant into hollowed out center of new pot and continue to fill in around the base. i would personnally bury they lower 2-3 incehed of the stem since there is not any lower growth. a tomatoe cage will work, i just prefer stakes. which ever you use, put it in the outer, newer soil so as not to pierce any roots, you dont want to wait because the roots grow quick. be sure to water with room temp water that has sat for at least 24 hours to allow the excess gases to excape.