Levi, frankly - you're talking nonsense. It's actually very easy to establish a nursery, and any nursery that follows the programme approved by the Ministry of Education can obtain a monthly grant (up to 75% of the money that a public nursery receives, or 100% if it follows certain additional requirements).
It doesn't take "an incredible high amount of time" - and in fact, the director of the nursery isn't even required to be qualified. Normally, anyone opening a nursery will obtain the building in/around February, recruit for new children until the end of April (in many towns and cities, public nursery places will fill very very quickly) and have all the paperwork completed by the end of May. That leaves June-August for equipping the nursery and completing the recruitment process for new staff.
On a different note, she has around 150k$. Can she establish her business of children nursery? any advises?
Absolutely. She won't need so much - it could be done on roughly $50k or even less.
and whether there is a market for an expensive private nursery in some part of that town.
Doesn't have to be an expensive private nursrey, to be fair. Creches are in incredible demand in Poland and yet very difficult to find places - if she opened one in a big city, places would go within days.
She will need to find English speaking staff for obvious reasons
In this case, the best thing is to find a good, capable director. There's a lot of nursery staff stuck on 2k net maximum that speak decent enough English that would bite the hand off someone offering 3k net to be the director.
It really depends on what she wants to offer. I'd say the marketplace is saturated with ridiculous "Eko-sportowo" type private nurseries, but there's still huge demand for public nurseries if you can make the finances work.