from what I can see reason for speech problem seems to be
* Severe affliction of second lord moon by Mars, Saturn and Ketu
* Natural karaka of speech Mercury which is also lagna lord in 8th house aspected by 6th house lord Mars from 5th house
Regarding education, she has combination of 4,5,9,11 houses across most planets showing very intelligent with ability to absorb conceptual topics especially in scientific fields/research. If she can keep her focus/concentration (with help from family), she can have a tremendous academic career in scientific fields
Her Moon Mahadasha from 29/6/2021 to 29/6/2031 seems good for education as Moon is placed in 11th house is in star of Venus (lord of intelligence) and has lagna lord Mercury as sublord. Given affliction to moon, concentration and anger challenges could arise.
Start of Mars Mahadasha from 29/6/2031 could be troublesome in studies as Mars is retrograde as well as 6th lord.
Strengthening her Mercury and Venus (either via gems or mantra) will help as most planets have Mercury/Venus as their sublord + these are her two prime planets for education as well.