Advice - Mother In Law & Sister In Law Family Visit Visa

Hi Guys,

Quick bit of advice as I am going to be applying for my Mother In Law & Sister In Law visa to Scotland, UK in next 3-4 weeks.

My Mother In Law had came 4 years ago on a 6 Month Visit Visa and went back around Month 4 and not been since and looking to bring her back but also my wife want's to get my sister in law to come.

I have the usual documents for Sponsor such as below.
Bank Statements (With Enough Balance)
Mortgage Statement
Utility Bill
Self Employed Self Assessment
Tax Documents
UK Citizen

My wife is a housewife but obviously have things on her name.

Last time I had used a immigration lawyer to do the application but read and heard from family and friends it's easy to do and better save money and do yourself.

While I can also pay for the whole visit and sponsor but I have been told it's better that my mother in law shows proof she can afford trip. (While she can as she is a Government Teacher but my sister in law stays with parents and father can financially support)

I am at loggerheads as shall I then on sponsorship letter mention that father in law will support visit or I can as well.

They have strong ties to Pakistan such as land, property, brother, sisters etc all them documents are all fine just more curious on sister in law stuff as she's not travelled outside of Pakistan but as is tradition and culture relies on parents support etc.

Thanks