What if you provide some fatwa or references that says there is no problem with age gap .. something like
http://islamqa.org/hanafi/askimam/15881
or
https://islamqa.info/en/146882
Tell them that these are authentic sites and a fatwa means a verdict on certain questions and our scholars opinions are documented in these links.
Also these are Hanfi sites so you can quote this
The state
religion in Pakistan is
Islam, which is practiced by 96% of the population. Freedom of religion is guaranteed by the Pakistan constitution. The Pakistani constitution established a fundamental right in which all Pakistani citizens irrespective of Religions have equal rights.
[2][3][4][5][6] The remaining four practice
Hinduism,
Christianity,
Sikhism and other religions.
[6][7]
Muslims are divided into the following
sects: the majority of them practice
Sunni Islam,
[8] while 5–20% are
Shias.
[8][9][10][11] Nearly all Pakistani Sunni Muslims belong to the
Hanafi Fiqh Islamic law school.
https://en.wikipedia.org/wiki/Religion_in_Pakistan
