She became Muslim after having an illegitimate pregnancy aborted; will Allah forgive her and will she meet her child in Paradise?

Firstly: 

Zina (fornication or adultery) is forbidden and is a crime
according to all divinely revealed laws. It is abhorrent and is rejected by
anyone with sound reasoning, even if he is not Muslim. Allah, may He be
glorified and exalted, has criticised the one who does it in many verses and
in many Prophetic hadeeths, and He has warned the one who does it of severe
punishment in this world and in the Hereafter. For more information please
see the answer to question no.
97884 

Secondly: 

If a woman commits zina and becomes pregnant, it is haraam
for her to abort the foetus after the soul has been breathed into it,
according to scholarly consensus, even if the pregnancy resulted from zina,
because it is a soul that is protected according to sharee‘ah. 

The soul is breathed into the foetus after one hundred and
twenty days. 

In al-Mawsoo‘ah al-Fiqhiyyah (2/57) it says: No
difference of opinion is known among the fuqaha’ concerning the prohibition
on abortion after the soul has been breathed into the foetus. They stated
that once the soul has been breathed into the foetus, it is haraam to abort
it, according to scholarly consensus, and they unanimously stated that this
is murder. End quote. 

Thirdly:

If a person commits bad deeds and is encompassed by his sins
when he is in a state of kufr, such as zina, stealing or other major and
deadly sins, then he becomes Muslim, Allah will forgive him for what he did
when he was in a state of kufr, then he will start a new page with his Lord.
Allah, may He be exalted, says (interpretation of the meaning):

“Say to those who have disbelieved, if they cease (from
disbelief) their past will be forgiven”

[al-Anfaal 8:38]. 

Ibn al-‘Arabi (may Allah have mercy on him) said: Our
scholars said: This is a kindness from Allah, may He be glorified, that He
bestows upon His creation. That is because if the disbelievers (kuffaar)
indulge in disbelief (kufr) and crimes, and they commit acts of disobedience
and sins, and they cannot escape accountability, they would never be able to
repent or attain forgiveness. But Allah has made it easy for them to have
their repentance accepted when they turn to Him in repentance, and He
bestows forgiveness upon them if they become Muslim and erases everything
that has gone before; this makes it more likely that they will enter the
faith and accept the word of Islam, and it serves to soften their hearts and
encourage them to become Muslim. If they knew that they would be
nevertheless be accountable for what they did they would not repent or
become Muslim. 

End quote from Ahkaam al-Qur’aan, by Ibn al-‘Arabi,
2/398 

In Saheeh Muslim (121) it is narrated that ‘Amr ibn
al-‘Aas (may Allah be pleased with him) said: when Allaah put Islam in my
heart I came to the Prophet (blessings and peace of Allah be upon him) and
said: Hold out your right hand so that I might swear allegiance to you. So
he held out his right hand, but I withdrew my hand. He said: “What is the
matter, O ‘Amr?”  I said: I want to stipulate a condition. He said, “What do
you want to stipulate?” I said: That I will be forgiven. He said: “Do you
not know, O ‘Amr, that Islam destroys whatever came before it?” 

An-Nawawi (may Allah have mercy on him) said: “Islam destroys
whatever came before it” means: It erases it and wipes out its traces.” 

End quote from Sharh Muslim

In Fataawa ‘Ulama’ al-Lajnah ad-Daa’imah (24/296) it
says:  

If a person is sincere in his repentance from his sins, even
if it was associating others with Allah (shirk), zina, murder or
consuming people’s wealth unlawfully, and he regrets his past sins, and
restores people’s rights to them or they pardon him, and he follows that up
with righteous deeds, Allah will accept his repentance and forgive his sins;
indeed He will replace his bad deeds with good deeds. Allah says, describing
His righteous slaves (interpretation of the meaning): 

“And those who invoke not any other ilah (god) along with
Allah, nor kill such life as Allah has forbidden, except for just cause, nor
commit illegal sexual intercourse and whoever does this shall receive the
punishment.

The torment will be doubled to him on the Day of
Resurrection, and he will abide therein in disgrace;

Except those who repent and believe (in Islamic
Monotheism), and do righteous deeds, for those, Allah will change their sins
into good deeds, and Allah is Oft-Forgiving, Most Merciful.

And whosoever repents and does righteous good deeds, then
verily, he repents towards Allah with true repentance”

[al-Furqaan 25:68-71] 

“Say to those who have disbelieved, if they cease (from
disbelief) their past will be forgiven”

[al-Anfaal 8:38] 

“Say: O Ibadee (My slaves) who have transgressed against
themselves (by committing evil deeds and sins)! Despair not of the Mercy of
Allah, verily Allah forgives all sins. Truly, He is Oft-Forgiving, Most
Merciful”

[az-Zumar 39:53].

End quote. 

Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd ar-Razzaaq
‘Afeefi, Shaykh ‘Abdullah ibn Qa‘ood 

With regard to the foetus that was aborted before his mother
became Muslim, Allah knows best about him and what his situation will be on
the Day of Resurrection. 

See also the answer to question no.
107781 

And Allah knows best.