  Ni$_3$Al and Ni$_3$Ga are closely related materials on opposite sides of a
ferromagnetic quantum critical point. The Stoner factor of Ni is virtually the
same in both compounds and the density of states is larger in Ni$_3$Ga. So,
according to the Stoner theory, it should be more magnetic, and, in LDA
calculations, it is. However, experimentally, it is a paramagnet, while
Ni$_3$Al is an itinerant ferromagnet. We show that the critical spin
fluctuations are stronger than in Ni$_3$Ga, due to a weaker q-dependence of the
susceptibility, and this effect is strong enough to reverse the trend. The
approach combines LDA calculations with the Landau theory and the
fluctuation-dissipation theorem using the same momentum cut-off for both
materials. The calculations provide evidence for strong, beyond LDA, spin
fluctuations associated with the critical point in both materials, but stronger
in Ni$_3$Ga than in Ni$_3$Al.
