if possible, why not get your mum and sister, if you have one, to come here instead? i believe their visas would be valid for 3 months. that way, you'd have the support of your mum etc and the comfort of being at home here, where hubby is, no discomfort of travelling or passport processing?
This is a good idea if you can handle having your family around when the baby is born and living with you in the same house (unless they're going to stay in a hotel the entire time which is also possible, but expensive).
Let me just tell you my experience a bit. I said that I found living my mom in her house in the States when the baby was born a bit stressful. It was partly because it wasn't my house so I didn't have free reign. For example, breastfeeding was horrible for me--especially the first couple of months--and it was so bad that my breasts hurt so much that even having cloth up against them was unbearable so I was instructed to go braless and shirtless as much as possible by the lactation consultant. Well, this isn't really possible (unless you sit in one room with the door closed all day) in someone else's home where you're a guest and there are also other people coming in and out (for example, my younger sister who still lived at home's boyfriend).
Also, sometimes it was a case of "too many cooks spoil the broth." Dealing with a newborn is tough sometimes and my mom was working so she didn't have time to effectively help us out but she was around enough that I was getting advice from her all the time--which is okay up to a point. She meant well but in the hormonal state I was in it was difficult to have other people observing me as I tried to figure out the first few weeks of being a new parent. It seemed that try as they may to avoid telling me what they thought about the job we were doing, there were still those looks and sometimes opinions. So, that added to the stress. Sometimes, it is better just to be left to your own devices to "sink or swim" for a time and then just have family and friends nearby to call in for "reinforcement" if you really are drowning.
So, this time, my mom and her husband did come to visit us but it was a full month after the baby was born. I think it was better this way as it gave me time to physically be on my feet again and also to wait and see if I was going to have post-partum depression or go through a "crazy phase" and get that out of my system before we had guests. Even though guests may totally come here with the intention to be low-maintenance--at least for me, if I have guests staying with me it's harder to rest because I do feel obligated to be a good host--this is complicated if you're also dealing with hormonal flux and a newborn.
It was just better that my mom came a bit later rather than being here for the birth and leaving or staying the entire time. But, I do think it's important to have help when you have a baby--at least a part-time helper.
That's just my experience.