What evidence does she have that she saw Virgin Mary herself or what she imagined as Virgin Mary?
Many people think and imagine according to their thinking. We can not take their claim as reality.
There is no contradiction at all. Mary (Mariam in Arabic) is daughter of Imran as Quran mentioned (And Mariam daughter of Imran who guarded her chastity) (Sura 66, Verse 12). She is also known withing Bani Israel as sister of Haroon (O sister of Haroon , you father was never a bad person nor you mother was a bad woman) (Sura Mariam, Verse 16).
Joachim can be the name of Imran in another language.
Allah swt is unique in His essence.
He neither begat, nor was begotten,(112:3) nor has He any equal.’ (112:4)
But His creation is under His absolute power and as He determined to create Adam (may Allah's peace and blessings be upon Prophet Muhammad and his progeny and upon him) without any need for biological parents, in the same way His will was ordained to create Jesus (may Allah's peace and blessings be upon prophet Muhammad and his progeny and upon him) without a father.
إِنَّ مَثَلَ عِيسَىٰ عِندَ اللَّـهِ كَمَثَلِ آدَمَ ۖ خَلَقَهُ مِن تُرَابٍ ثُمَّ قَالَ لَهُ كُن فَيَكُونُ )3:59
Indeed the case of Jesus with Allah is like the case of Adam: He created him from dust, then said to him, ‘Be,’ and he was.