Marihaa (مرِحا, with a kasrah under the ر) could not be found in the lexicons. However, Marah (مرَح, with a fathah under the ر) means to sway with joy, to be beside oneself with excitement, to strut, and to sway one's body with pride. Given these meanings, this name is not suitable for a child.
Instead, a name from among the Ummahaat ul-Mumineen, the Sahabiyat, or any other name with a good meaning should be chosen.
Allah the Almighty knows best.
Darul Ifta Al-Ikhlas, Karachi.
القرآن الکریم: (اللقمان، الایة: 18)
وَلَا تَمْشِ فِي الْأَرْضِ مَرَحًا....الخ
القاموس الوحید: (ص: 1221، ط: ادارۃ اسلامیات)