They have a right to take your deposition, although they should subpena you (you are not obligated to cooperate). Your husband would have the right to seek a protective order if your deposition would somehow be outside the scope of discovery (I suspect this is unlikely). Good luck.
The author of this post is licensed to practice law in the District of Columbia, Maryland, and Virginia. This post is intended as general information only, and is not provided as legal advice in connection with any specific case, and does not create an attorney-client relationship.
If you are properly subpoenaed, you must comply, unless your husband or his company, whichever is the party to the action, moves for a protective order. I must tell you that it is unlikely that the subpoena will be quashed; almost certainly, you will be required to comply.
You have the right to a separate attorney to protect your personal interests, or the attorney for your husband and/or his company can represent you.
Your husband/his company can't move to quash because the other side said your deposition will be lengthy. But the attorney representing you can object to repetitive questions, and try to speed things along. Depending on the nature of the suit -- breach of contract, fraud, diversion of funds, etc. -- you might be better off with your own attorney.
I can't offer any Pennsylvania specific help as I'm not licensed there, but your question is falls into an area where the state laws are similar.
If you are subpoenaed you have to give the deposition. If you have not been subpoenaed then you don't have to, but they would probably just issue a subpoena in this instance if you refuse the deposition. The discussion above about quashing a subpoena or obtaining a protective order is correct and I don't have much to add to that discussion. If you have potentially relevant information or information that might lead to potentially relevant information the subpoena would not be quashed. If there is no way that you could have potentially relevant information or information that might lead to some then the court might quash the subpoena. This is a very broad summary of quashing a subpoena and there are other grounds upon which a subpoena could be quashed or a protective order granted depending on if this is in state or federal court. But this is a state specific area so it would be better for you to consult a Pennsylvania lawyer if you intend to file a motion to quash a subpoena. I will refrain from commenting on it further.
You might suggest that they depose your husband first as that might answer the questions that they have and create a record to quash any subpoena issued to you. As you don't appear to be a party to the case there may be witness fee or travel restrictions on where they can hold the deposition depending on whether the case is in state or federal court. There also may be length limits on how long they can depose you which again depends on the court the case is before. Again this is a state specific area so I will leave it at that.
If you are deposed your marital status with your husband may allow you to not answer certain questions. You would still have to show up and assert this privilege and answer any questions to which the privilege does not apply. The spousal privilege to refuse to testify altogether applies only in criminal cases. However, there is a marital communications privilege in Pennsylvania and most other states that applies in both civil and criminal cases. This privilege allows you to refuse to testify to marital communications. Again, you would still have to testify to questions that aren't related to protected marital communications. Martial communications are communications between validly married spouses that were intended to be confidential and were not made in the presence of a third party. The communication must relate specifically to the marriage. This privilege only applies to communications made while the spouses are legally married (not before marriage or after a divorce). It does not apply in cases of abuse, where both spouses perpetrate a fraud on third parties, or where there is a co-conspiracy between the spouses.