First of all, if you haven't your epiphyseal plates closed, not any minimum serious competent doctor in the world will make the surgery. This may be a good thing to you because women still naturally grow, generally not much (but sometimes still considerably) until the plates close which may be somewhere between you are around 18 or 24 years old.
While you "wait" don't stop exercising, stretching and maybe taking supplements of calcium, vitamin D (also catch lots of sun because that produces natural vit. D in our skin), iron (to better assure plenty of oxygenation and nutrition of tissues. Don't forget of course a good, balanced nutrition, without getting fat!
I would advise you also to have psychological counselling or a serious coach to develop your self esteem and help you start making your life projects starting now.
Second, go to an endocrinologist consultation to check your height and future predictions (also to order Rx to your epifhyseal plates). After that he may prescribe or not injections of human growth hormone Note however that these not allways have any result, specially in your age (you are 15?). Sometimes the body like reduces its own production of the hormone and it sort of "compensates" for the intake of artificial hormone.
Third, when you have your plates closed, if you have still the "problem", keep or get counselling specifically mentioning LL (ideally you may speak about that from the first day you have counselling). Explain all the procedure to the psychologist: the amount you can grow with minimum risk, all the possible risks, etc. Also what concretely makes you feel bad about your height with practical examples.
Fourth: if after, let's say, at least two years you still want LL, start researching who are the 3 best, more experienced LL surgeons, and go to a consultation personally with all 3, regardless of costs. You mustn't enter into the LL project without all the advisable financial resources including forecast of possible complications and their treatment. Take a systematic list of questions and also evaluate the empathy you feel with them. Try to know through them and the forum if he stands by after surgery during the elongation process (and accessible preferably also in the consolidation phase). Be sure that it's really him that will make the surgery (Pale only operates one leg and then "disappears" and you get alone with a faceless team where nobody cares according to some members of this forum).
Finally, be wise! Take into account the average height in your country of residence or future residence, ear the doctor and NEVER have as an objective to grow past 5,5 cm if you do tibias alone (or 20% of their height), and 7 cm if you do femurs alone (or 20%, whichever is lower). I wouldn't advise you to do both, resist that temptation to reduce risks at all cost. If you go for both, don't exceed the total of 20% of the leg or 11 cm in total.
If choosing tibias or femurs I suggest you mock a picture and as you are a girl and maybe care more about legs beauty, do tibias, contrarily to the more frequent advice here: if you do femurs, when you are with skirts, in the beach, or even nked with your boyfriend, you will have your knees too close to the ground). However, with tibias elongation and consolidation will take more time and patience (femurs are "easier" and may be elongated more, and its the main reason they are more popular).
Choose the LL method wisely after analysis with all possible sources. Don't choose necessarily "modern", "fashion" nails. You can even go with the cheapest but also tested and improved since 70 years ago Ilizarov type of externals. But beware as these are not confortable at all and you have to take extra precaution to diminuish risk of pin infections, despite these are allmost allways easy manageable.
If your are obese at that point you must address that, ie, have never more than 20% maximum of body fat and a good percentage of muscle (not less than 32% but check your case and body with the doctor).
Talk to the doctor and some physiotherapist (it would be a bad sign if the doctor didn't have them in the team, or close to). Start a targeted physical intensive physical preparation at least one month before surgery (ideally, the sooner the better, like...today!). Get muscular mass calculation among other tests 1 month before and after, nearer the date foreseen for the surgery.
Allways keep psychological support and also from your family and one or two closest friends and boyfriend if you have. Get assured somebody will allways be with you all the LL time, even if it's somebody hired.
Assure yourself that you get the necessary regular Rx and doctor's direct, close and dedicated follow up.
Follow all his advise and prescriptions. Never ignore anti embolism medicines, feed yourself with a lot of proteins (meat and dairy products, maybe also supplementary, as well as calcium, magnesium, and also iron. Iron is to improve a good supply of oxygen it carries to the new tissues in need to grow.
And of course never do less than advised hours of physical exercice.
Really finally: check at all costs that you have height neurosis before LL. It may be just an adolescent phase.
5"4 is REALLY OK for a girl in the whole world!
Don't take the risk, spend the time and the money. Concentrate on your personal development instead: skills, education, travel, normal routines (not painful LL routines...)!!
Good luck!