We investigate the standard stable manifold theorem in the context of a partially hyperbolic singu-larity of a vector field depending on a parameter. We prove some estimates on the size of the neighbourhood where the local stable manifold is known to be the graph of a function, and some estimates about the derivatives of all orders of this function. We explicitate the different constants arising and their dependance on the vector field. As an application, we consider the situation where a vector field vanishes on a submanifold N and contracts a direction transverse to N. We prove some estimates on the size of the neighbourhood of N where there are some charts straightening the stable foliation while giving some controls on the derivatives of all orders of the charts.