Maybe, there are multiple accounts of Muhammad's life which all vary on certain details such as this.
According to various ahadith* Aisha was probably 6 or 7 years old when she married Muhammad, this marriage was consummated at age 9.
She was 6 according to Sahih al-Bukhari (emphasize mine):
that the Prophet married her when she was six years old and he consummated his marriage when she was nine years old, and then she remained with him for nine years (i.e., till his death).
Volume 7, Book 62, Number 64
She was 7 according to Sahih Muslim (emphasize mine):
Aisha (Allah be pleased with her) reported that Allah's Apostle (May peace be upon him) married her when she was seven years old, and he was taken to his house as a bride when she was nine, and her dolls were with her; and when he (the Holy Prophet) died she was eighteen years old.
Please note: there is a gap of roughly 200 years(!) between the moment these ahadith were written and the actual wedding.
There are other sources who disagree that these ahadith are accurate when it comes to Aisha's age.
According to muslim.org (emphasize mine):
As to the authenticity of these reports, it may be noted that the compilers of the books of Hadith did not apply the same stringent tests when accepting reports relating to historical matters as they did before accepting reports relating to the practical teachings and laws of Islam.
The reason is that the former type of report was regarded as merely of academic interest while the latter type of report had a direct bearing on the practical duties of a Muslim ... Thus the occurrence of reports such as the above about the marriage of Aisha ... is not necessarily a proof of their credibility.
They also give 10 as an alternative age (emphasize mine):
... Aisha came to the household of the Holy Prophet in the second year after hijra. So if Aisha was born in the year of the Call, she would be ten years old at the time of the nikah and fifteen years old at the time of the consummation of the marriage.
There are broader estimates as well.
Wikipedia lists this source in the footnote which says it can be anything between 13 and 19 (I can't find an online version) (emphasize mine):
Muslims who calculate 'Ayesha's age based on details of her sister Asma's age, about whom more is known, as well as on details of the Hijra (the Prophet's migration from Mecca to Madina), maintain that she was over thirteen and perhaps between seventeen and nineteen when she got married.
Barlas, Asma (2012). "Believing Women" in Islam: Unreading Patriarchal Interpretations of the Qur'an." p. 126.
*Ahadith is the Arabic plural of hadith.