She did Hajj ifraad with her husband and they failed to do sa‘i

Praise
be to Allah

Sa‘i is one of
the pillars or essential parts of Hajj, without which Hajj is not complete,
and the muhrim (pilgrim in ihram) cannot exit ihram completely until he has
done it. As for the first stage of exiting ihram, after which everything
becomes permissible except intercourse, that is attained by stoning the
Jamrah and shaving the head. Then when the muhrim has done tawaf and sa‘i,
he has completed the second stage of exiting ihram, and everything becomes
permissible to him.

The pilgrim who
does Hajj ifraad [Hajj only] is only required to do sa‘i once, so if he does
sa‘i after tawaf al-qudoom (the tawaf of arrival), that is sufficient for
him.

Based on that,
if you did not do sa‘i after tawaf al-qudoom, then you are still in a state
of ihram; you have not completed the second stage of exiting ihram and it is
not permissible for your husband to have intercourse with you until you exit
ihram, by doing sa‘i.

If intercourse
has taken place during this period due to ignorance of the ruling, then you
do not have to do anything, but to be on the safe side you may offer a
fidyah (penalty), which involves slaughtering a sheep, or feeding six poor
persons, or fasting three days, which is required from each of you.

But you cannot
exit ihram completely except by doing sa‘i.

You must also
ask Allah for forgiveness and repent from this shortcoming and heedlessness,
for you have not performed the rituals as enjoined by Allah, and you did not
ask scholars or people of knowledge throughout this lengthy period, even
though you live in Makkah and it is easy for you to do sa‘i.

Shaykh Ibn Baaz
(may Allah have mercy on him) was asked: I am a resident of Makkah. I did
Hajj last year, and I did tawaf but I did not do sa‘i. What is the ruling?

He replied: You
have to do sa‘i. This was a mistake on your part. It is essential to do sa‘i
whether you are a resident of Makkah or otherwise. It is essential to do
sa‘i after tawaf; after you come back from ‘Arafah you must do tawaf and
sa‘i. The one who omitted to do sa‘i must do sa‘i now. If he has had
intercourse with his wife, then he must offer a sacrifice to be slaughtered
in Makkah and given to the poor there, because he cannot complete the second
stage of exiting ihram except by doing sa‘i. So he must do sa‘i now with the
intention that it be for his previous Hajj, and he must offer a sacrifice if
he has had intercourse with his wife since then. End quote from Fataawa
ash-Shaykh Ibn Baaz (17/341).

Shaykh Saalih
al-Fawzaan (may Allah preserve him) said concerning someone who did Hajj but
failed to do sa‘i because he was unable to walk or to hire a wheelchair:
With regard to failing to do sa‘i, this was wrong, because it is obligatory
upon you to complete all the rituals, and sa‘i is a pillar or essential part
of Hajj, without which Hajj cannot be complete. If you entered ihram for
Hajj on its own (ifraad), or for Hajj and ‘umrah together (qiraan), and you
did sa‘i after tawaf al-qudoom (the tawaf of arrival), then you do not have
to do another sa‘i after tawaf al-ifaadah. But if you were doing tamattu‘
[Hajj after doing ‘umrah then exiting ihram, then entering ihram again for
Hajj], or you were doing qiraan or ifraad and you did not do sa‘i after
tawaf al-qudoom, then sa‘i remains due from you, so you must go and do sa‘i,
seven laps between as-Safa and al-Marwah, with the intention of doing the
sa‘i of Hajj. If you had intercourse with your wife during this period, then
you must offer a compensatory sacrifice of a sheep, the meat of which is to
be distributed among the poor of Makkah, and when you want to go back to
your own country, you should do the tawaf of farewell.

End quote from
al-Muntaqa min Fataawa al-Fawzaan.

And Allah knows
best.