The two of them had been fast friends after that. They were almost always in one another's company. They were, more often than not, joined by Neville Longbottom who seemed to not get along with Ron any better than they did. Unfortunately this had made him somewhat of a pariah within his own house. Since Ron's friend Dean and Seamus tended to side with him and then the three of them picked on the odd person out.
Iris had wanted to hex Ron Weasley, whom she already detested, to within an inch of his life. Thankfully, Ron had twin brothers who were in the year group ahead of theirs who were casual friends with Iris and had the added benefit of being in Gryffindor for ease of access and who felt the same. They had spent the next two months pranking Ron mercilessly in retribution. He barely made it through half a day without one or two pranks going off directed at him.
Their adventures hadn't stopped there. Again, with the aid of the twins they had helped smuggle a dragon out of the school and to the reserve to the twins' brother Charlie in Romania.
Then there had been the awful confrontation at the end of the year in order to stop Voldemort, in possession of Professor Quirrell. The professor had lured Dumbledore to the ministry for the day. Quirrell had also tainted the food in the Great Hall, and fully half of the school had come down with a violent illness. All of the teachers were required to help, and it had been the perfect distraction.
Hermione, Iris, and Neville had faced a gauntlet set up to trap anyone getting the stone. Though they had found the traps relatively easy to overcome. Hermione hadn't been able to be there with Iris when she had confronted Quirrell, but had gone back for help with the logic trap. She had however waited by Iris' bed almost non-stop after the incident until she woke up.
The second year had arguably been worse. The Chamber of Secrets had been opened by Ginny Weasley, though she hadn't done it on purpose. She was possessed by a diary of one Tom Marvolo Riddle, who they later discovered was the real name of Lord Voldemort, who apparently had a fondness for anagrams.
This was after the entire school turned on Iris, thinking she was the Heir of Slytherin when it was revealed she was a Parselmouth. Ron Weasley of Gryffindor and Theodore Nott of Slytherin practically had most of the student body burning Iris in effigy. It was something Hermione thought was silly. As if being able to communicate with an animal made you evil.
After one of their fellow Ravenclaws, Penelope Clearwater, had gotten petrified, and one of Iris' twin sister's friends, Luna Lovegood, got petrified they realized what was causing the petrifications. When Ginny Weasley was "abducted", Iris and Hermione had both realized where the entrance was, and they descended into the Chamber of Secrets.
They had both gone down and faced Salazar Slytherin's thousand year old basilisk, controlled by the fifty year old memory of Lord Voldemort at age 17. They had both gotten bitten by the basilisk. Hermione got bitten on the leg, before Iris stabbed the basilisk in the nose with the sword of Godric Gryffindor that had been brought to them by Dumbledore's phoenix and the Sorting Hat.
Of course stabbing it in the nose had just pissed it off, so it released Hermione and turned on Iris. This time it tried to bite her, Iris had stabbed it through the roof of its mouth, getting bitten in the process. Hermione had used that distraction to do the only thing she could think of. She took out the tooth that remained imbedded in her leg and stabbed the diary that had started all of this with the tooth.
Hermione remembered the ghost of Tom Riddle screaming in pain and jumping into her in a last ditch effort to survive. She remembered a lot of pain and a struggle of wills before he was forced out. Then she passed out. She woke up in the infirmary almost two days later.
This time it was Iris who had been waiting by her bedside for her to wake up. When Hermione asked what happened, Iris told her that Tom had been trying to possess her forced out by a combination of her will, buffered by the song of the Phoenix. Iris had also told Hermione that Fawkes had saved them both by crying in their wounds, but that it took Hermione longer to recover because the basilisk venom had been in her system longer, and that they had almost lost her.
Their third year together, they hadn't had many adventures per se, as long as you didn't count the constant threat of a crazed Bellatrix Lestrange repeatedly attempting to get into Hogwarts in an attempt to kill Iris. They had stuck together everywhere, and Hermione had refused to let Iris out of her sight for any reason.
Bellatrix had made it to the portrait multiple times but never managed to make it into Ravenclaw Tower itself. Iris' godfather Sirius and her father James had taken to alternating nights bunking in the common room of the tower in order to be another line of defense.
However Bellatrix had cornered Iris and Hermione during a trip to Hogsmeade. That attempt had been driven off when Iris' mother and Severus Snape had showed up and Lily had dueled Bellatrix to a standstill, while Severus Snape had held off a second cloaked death eater who had attempted to get the drop on them. Both Bellatrix and the mystery Death Eater were forced to flee.
Severus Snape had never been either Iris or Hermione's favorite teacher, they felt he went out of his way to be cruel to them, and though it paled in comparison to the treatment that Gryffindors received, and it had never gotten completely out of hand. Though it was also fair to say he never showed any favoritism towards them despite his friendship with Iris' mother.