The WA assault statutes are here: http://apps.leg.wa.gov/RCW/default.aspx?cite=9A.36 .
Under the state's statutes, assault in the fourth degree is the lowest of the four possible levels and is a gross misdemeanor. A gross misdemeanor has a maximum penalty of up to year in jail and $5,000.
If she is charged by a city, the city may set lower penalties.
Domestic Violence (DV) likely means she is accused of assaulting someone who is living with her or someone she used to have an intimate relationship with.
If your daughter is not a US citizen, a DV conviction (against certain household members) or guilty plea is a basis for deportation from the US.
The charging document should have the statute or ordinance cited.
Being 18 or older, your daughter likely is charged as an adult. If so, you are not legally responsible for her legal fees. Of course, you can help her out financially if you want.
If your daughter is low income, she likely qualifies to be appointed a public defender.
She has the right to hire a private attorney if someone is willing to pay the attorney.
In Washington State, there is a mandatory hold period for persons charged with DV.
You should get a good attorney right away. An Assault in the Fourth Degree Domestic Violence carries a maximum penalty of 365 days in jail, a $5,000 fine, and a loss of your right to possess a firearm.
Further, the judge could order a no-contact order between your daughter and the alleged victim, and any violation of that order could be charged as a crime.
This is a serious matter, and you should not fight this alone.
Assault IV is a gross misdemeanor in the state of Washington, punishable by up to 1 year in jail and a $5,000 maximum fine. The "DV" Classification stands for Domestic Violence and it describes an Assault IV that was committed against a person with whom the defendant has a certain type of relationship, such as being family members, romantically involved or married, or even roommates.
People arrested for DV Assault IV are typically held in jail pending their arraignment. An arraignment is the first appearance in a criminal case and it is a process where the judge informs the defendant of their charge, the maximum sentence, and what their rights are (such as the right to an attorney). The judge will also decide whether the defendant should be released pending trial and what conditions, if any (such as bail, electronic home monitoring, etc.), there should be. The judge will make a decision taking into account things such as ties to the community, safety of the alleged victim, likelihood of flight, and other factors.
Family members can be helpful at arraignment, and of course they can also be helpful in terms of posting bail if the judge requires it.
Since she is charged with a crime, your daughter has the right to be represented by an attorney: either a public defender, if she qualifies, or she may retain someone if she does not. The judge should tell her at arraignment how she can screen for a public defender. Her attorney can then help explain the rest of the process for her, her rights, and counsel her the rest of the case.
Good luck to you and your daughter,