Welcome to HealingWell,
Not trying to be impertinent, but your daughter's health should come first and foremost. There are risks associated with ablation, but there are risks associated with some medications as well. A quick look shows Beta Blockers (most Beta Blockers are "genuinely" considered safe to initiate without monitoring, with the exception of Sotalol, a Beta Blocker with Anti-Arrhythmic properties that requires monitoring in a hospital for 48 hours or more for the initial dosing) and Calcium Channel Blockers (usually regarded as safe to initiate without monitoring, but I'm not sure of exceptions) as initial medications in treating SVT.
SupraVentricular Tachycardia derives it's name from Supra (above) Ventricular, literally, "above the ventricles" and Tachycardia (heart rate over 100 beats per minute). Our heart's normal pacemaker, the SA Node, is above the ventricles as well, in the atrium of the heart. Supraventricular Tachycardia is not usually considered dangerous, especially contrasted to Ventricular Tachycardia, which is a fast heart rate originating in the ventricles.
In my non medical opinion, if given the opportunity to try a Beta Blocker, I would go that route first. Another thing that I would suggest is a second opinion from a doctor not associated with the original doctor. I went through several months of very frequent ectopics, PVCs and PACs, saw what I believe to be a credible Electrophysiologist, and despite the 6000 PVCs a day, he said they weren't harmful in nature. But I was emotionally distraught by the frequency of them.
It became apparent to me that he wasn't listening to me. I had just had my second Holter monitor this year, told him we called his office and they said the results were in, and he sat there telling me why it takes several days to get the results. As I was preparing to leave, he asked his nurse to send me the results when they came in, and she told him the results were there, she had told him so that morning, and the paper copies were in with his paperwork and the results on the computer. He also tried to give me a prescription, which I didn't want, and he got agitated. When I asked about medication I was taking for seizures, only then did it occur to him that my current medication is related in nature to the one he was trying to prescribe, and the one he offered probably wouldn't work. I thought he was supposed to think these things through on his own?
Of course he offered an ablation. But my ectopics were multiform (multifocal) and I serious doubt that they would have found all the foci. I started drinking 1 Ensure, 1 Carnation Instant Breakfast, and 1 Vitamin Water (not energy drink, just 100% of B Vitamins and had Potassium), and eating one banana, and within a week, went from 3900 ectopics a day to dozens to less.
I was cautioned in the past by a cardiologist that ablation can make things worse. Hazards of ablations include the chance of dislodging a clot. Ask the doctor if he/she knows where the ablation will probably need to be performed. The heart consists of 4 chambers, 2 atrial and 2 ventricular. Blood returns to the Right Atrium, pumps to the Right Ventricle, pumps to the lungs, returns from the lungs to the Left Atrium, pumps to the Left Ventricle, then pumps to the body, including flow to the brain. Ablation in the right side of the heart, if a small clot is liberated, would go to the lungs, and because of the Alveoli in the lungs, passage of all the blood through capillaries, clots are isolated there, and if they're small, do no harm. A clot liberated by a left side ablation can cause a stroke, or may travel to another area of the body, where it wouldn't do any harm.
Being that your daughter is young and athletic, the odds of clots may be reduced, and the odds are low to begin with in most people. SVT seems to lend itself more to successful ablations more than PVCs or PACs.
Hope this is of some help.