Suhannah, pronounced as (SOO)n + (HA)rd + (NU)mber, is an ancient Arabic name without a clear meaning, it comes from the SAD-W-H6
root which has meanings of "dryness". It is not a Quranic name, but since it doesn't have a
bad meaning it is acceptable to use it. It also has a
male version, Suhan or Soohaan. It can also be spelled as Suhana, Suhaana, Suhanah, Soohana, Soohanah. It is spelled as صوحانة in Arabic.
From what I can find Suhana is also a Hindi name meaning "
beautiful", "lovely". Since it has a
good meaning, it is acceptable to use it. This is probably the name you are asking about. It is probably pronounced with a quicker Su sound than the Arabic, as in (S)ummer + p(U)t.