I.
If you were accustomed to fasting from an early age, then in principle it may be assumed that you fasted, so do not pay any attention to uncertainty.
If you were not accustomed to fasting from an early age, then what appears to be the case that it is permissible to act on testimony of others, so you should ask your family. If they say that you did fast, then you do not have to do anything. Their testimony indicates what is likely to be the case, and rulings may be based on what is most likely to be the case, just as they may be based on what is certain.
One of the principles of jurisprudence is that acting on the basis of the strongest opinion is permissible.
Dr. Muhammad Sidqi al-Burnu said in Mawsa`at al-Qawa`id, 7/456: What is meant by the strongest opinion is that which is most likely to be correct.
What this principle means is that when there is no certainty, what is thought most likely to be the case is sufficient to base rulings on, because certainty in most rulings is not possible. End quote.
II.
If it is not thought most likely that you fasted, then you must make up the fasts, because in principle, it is assumed that you did not do that.
Al-Qarafi said in Al-Furuq, 1/227: If a person is unsure whether he fasted or not, then he must fast. End quote.
All of this applies if the one who is asking the question is not affected by intrusive thoughts (waswas). If she is affected by that, then she does not have to do anything, and she should not pay any attention to the intrusive thoughts.
And Allah knows best.