For me, when I gave birth to my first child, I didn't have a helper and was even opposed to having one. After I had a really rough recovery from childbirth that left me immobile at times with back problems, my husband hired part-term local help which was greatly needed.
I had such a hard first 18 months with my son that I thought I would probably never have any more children. Then when my son was about 2-years-old we hired a full-time helper who is amazing and capable. The possibility of perhaps having more children became something to consider for me--only at that point. So, when my son was 2.5-years-old I got pregnant again.
For me, personally, I would not want to have small children without help for many reasons--especially with two children. Yes, many women around the world do take care of 1, 2 or many more children without the benefits of a helper but there is a price to be paid for that. It is totally possible to do so but I often talk with a close friend in the States who is managing her nearly 3-year-old and her 9-month-old by herself without a helper and she really struggles. Getting a spare moment to even take a shower or have a few minutes of "me-time" is rare for her. It's even worse when one or both of her children gets sick--which has happened a lot this winter--not to mention if she gets sick too.
The strain has even started to put her health at risk and has been hard on her marriage as well. Every time I hear about the things she's going through two things go through my mind 1) I remember those times that brought me right to the brink of sanity in my own life 2) I am so, so, so thankful we have a good helper.
Yes, I could definitely manage without a helper but I don't think I would like that life very much. That's just my personal experience. So, for now, with small children, I'm thankful to have help.
As far as second child goes...I think it's much better than the first--at least for me. The situation with your helper sounds sticky. I don't know what protocol is for handling the situation where a helper falls pregnant during her contract. The first part-time, local helper I had was 8 weeks pregnant when we hired her and she worked until she was about 6-months-pregnant. However, her workload only really included watching my son--very little, if any, household chores or cleaning.
If I were in your shoes, I would to my best to get a helper on board who is capable and great to work with before my second child was born. Good luck and congratulations!