Should I take admissions to this phd programme?
To me this arrangement is the greatest chance you could get to work under the supervision of whom you requested in the future. Since you have such strong orientation towards that particular supervisor (at least the way I see it), I think you should take the offer.

However, if all you want is to secure a good Ph.D. position, you should take into account whether you are ready to accept the worst case scenario, which is she refuse to take you in and you have to work under the supervision of the other supervisor. If this is the case, none of us here can help you in the decision making.