Visa Rejected for Sister but approved for Dad- Family visit

Hi,

I recently applied for my dad and sister family visa to come and see my family as my wife. We are expecting second child so that was the main reason. My dad has got visa approval but my sister was declined and the reasons are as below. The application was made in Pakistan. My sister is dependant on my parents and unemployed she do not have any lands or etc on her name. We did explain she is getting married in Dec 2015 and she would like to visit before getting married. We did not have any wedding cards but explain that in our application. She was not given any appeal right as well. The refusal say the following.

You have stated that you intend to travel to the UK for a period of 8 weeks to visit family i understand the importance of family ties and I have considered your application careful from the information provided in your visa application form and any documents submitted and support of your application. • In applying for entry clearance as a visitor. the onus is on you to demonstrate that you intend to comply with the terms and conditions of your visa and that you will leave the UK at the end of your proposed trip. You state that you are unemployed with no income of your own. You are single with no one dependent on you and you have not demonstrated what level of support you are in receipt of. You have no savings, investments. properties or assets in your name and therefore I am not satisfied that you have demonstrated a strong incentive to leave the UK at the conclusion of your visit. • I have considered the evidence and information submitted in your application: and on the balance of probabilities I am not satisfied that you have accurately presented your circumstances or intentions in wishing to enter the United Kingdom. This undermines the credibility of your application to the extent that I am satisfied that you are genuinely seeking entry as a visitor or intend to leave the UK at the end of your visit Paragraph V 4.2 (a) (c) of the Immigration Rules. Future Applications

She has been given U.K visa in the past (2011) when she visiting us for first child birth but has been rejected this time even though I think the previous application in 2011 had less explanation about the her visit visa and it was exactly same circumstance as we have today.

I want to make a new application but dont know how to cover these points. Any pointers will be helpful.