My 9 year old difficult child has that combination of diagnosis's. And, medication has been difficult because we have to work on so many issues at the same time. My husband started out adamantly opposed to medications, but over time came around because we were not making any progress without medications and difficult child was miserable.
To start, the parents are going to need to familiarize themselves with the various classes of psychiatric medications, because their daughter probably will need several. I recommend, " Straight Talk About Psychiatric Medications for Kids," by Timothy Wilens.
Our difficult child's tics have never been the primary issue. They are bothersome to him, but have not impacted his life in the way that his mood cycling and aggression has. So, for us, regulating his moods and dealing with aggression have always been the most important issues. difficult child's Obsessive Compulsive Disorder (OCD) has been serious, but has always taken a backseat in treatment plans because it is hard to do anything about the Obsessive Compulsive Disorder (OCD) without first getting the moods under control (since Obsessive Compulsive Disorder (OCD) is best treated with SSRIs).
With this diagnosis combination, some psychiatrists argue for going straight to the atypical APs because they work well with aggression and also help with tics. And, many psychiatrists argue that the atypical APs also have mood stabilizing qualities (which we have found to be true for difficult child). However, given the parents' position on medications, this might be a difficult step for them to take. If their daughter does NOT have a lot of aggression and her tics are NOT a major concern, then starting with a mood stabilizer instead of an AP could be a sound position.
A note on AP side effects: husband and I were very worried about trying APs. The side effects just sounded too horrendous to even risk. But, we eventually had to try them because difficult child's progress on mood stabilizers had stalled. difficult child has tried Abilify, Seroquel, and Risperdal. None of them are perfect. All three have been effective for difficult child's tics, though he eventually developed akathisia (restlessness and muscle twitches) on Abilify. These symptoms were very different from his tics and there was no question of confusing the two. One advantage of Abilify is that it generally does not lead to the weight gain that other APs often cause. Of the three, we have found Risperdal to be the best for difficult child. It did cause some short term weight gain, but with a good diet and plenty of exercise it has not been a major concern.
The mood stabilizers: As I said above, if aggression and tics are NOT major concerns, then maybe a mood stabilizer is a good place to start. Many people think Lithium is scary (I used to), but that might be a good place for the parents to start their research, especially if their daughter's moods tend towards mania rather than depression. Lithium has not been a cure-all for our difficult child, but it did give us a huge step in the right direction and I think our subsequent progress would not have been possible without it. Lithium has been around for a long time and its dangers and side effects are well-known. It does require somewhat frequent blood draws, but our difficult child (who generally is not a very cooperative child) does well with them.
We have also had good luck with Trileptal (and no side effects), though it did not work for difficult child long-term.
Finally, the SSRIs: We tried both Zoloft and Prozac when difficult child was only diagnosis'd with Tourette Syndrome. Disaster! Both caused mania, so we were very reluctant to ever try an SSRI again. However, difficult child's Obsessive Compulsive Disorder (OCD) eventually got bad enough that we had to do something. With both a mood stabilizer and AP already on board, we decided to try Luvox. difficult child's Obsessive Compulsive Disorder (OCD) abated in three days. Getting the Obsessive Compulsive Disorder (OCD) under control has made a huge difference in his quality of life, but we couldn't do that until we had his moods under control. I have since read that Luvox is a good SSRI to start with because it has a very short half-life, so if it does cause mania it will get out of the child's system faster than others.
I wish your friends and their daughter luck!