you have a wrong concept. If you think that before Islam or hinduism woman through the history was always treated as slave, it is wrong.
If you go through Christianity, Mary ( Bibi Mariam (R.A)) had a dignified status in the society and there are so many examples before it.
The right we are talking about is LIKE GIVING HER A SHARE IN PROPERTY, GIVING HER THE RIGHT TO ACQUIRE KNOWLEDGE,
which before Islam was never given to woman. . .
These were already there in hindusim long before where the women had equal rights to the property of father.
"Arthashastra and Manusamhita are sources about the woman's right to property or Stridhan, (literally meaning, property of wife). It is of two types: maintenance (in money or land given by the husband), and anything else like ornaments given to her by her family, husband, in-laws and the friends of her husband. Manu further subdivides this into six types - the property given by parents at marriage, given by the parental family when she is going to her husbands house, given by her husband out of affection (not maintenance which he is bound to give), and property given separately by brother, mother and father [Manu IX 194]. Pre-nuptial contracts are also mentioned where the groom would agree to give a set amount of brideprice to both parents and the bride. Such property belonged to the wife alone and was not to be touched by the groom or her parents except in emergencies (in sickness, in famine, threatened by robbers, or for performing holy deeds). At the same time, the Manu Smriti contradicts itself by declaring that a wife has no property and the wealth earned is for the husband [Manu VIII.416].
Daughters and sons equally inherited their mother's property; but some scriptures insist that a mother's property belongs solely to the daughters [Manu IX 131], in order of preference: unmarried daughters, married but poor daughters, married and rich daughters. When a father died, unmarried daughters had to be given a share in their fathers property, equal to one-fourth from every brother's share [since it is assumed that the married daughter had been given her share at marriage] [Manu IX. 118]. If the family has no sons, the (appointed) daughter is the sole inheritor of the property [Manu IX 127]."
Regarding right to education
"Katyayana's Varttika 125, 2477 mentions that there were female teachers of grammar. Patanjali wrote in his comments to Ashtadhyayi 3.3.21 and 4.1.14, that women undergo the thread ceremony before beginning their education, and says that women studied grammar."