To ask if she overstepped the boundary or if I’m being unreasonable?

This.

Your DH is right though, she is needy.

I think @Holdinguphalfthesky’s response is the best one.

I think she’s needy as well. She’s never contacted you before, is a virtual stranger, and yet she was on the phone to you for over an hour last night, and she’s already texting you this evening. Also, it’s the evening (well night now) and it’s the weekend, so double-whammy-outside hours. I know you mean well, and want to help, but in less than twenty four hours, she’s contacted you twice. How many of your regular friends have you had this much contact with?

I think there are two things going on here. I am not sating that the OP's husband has handled this well but I do think he might have a point.

I interpret it differently. I think the dh has issue with the person contacting her, not that his wife was supportive. He feels his wife’s customers shouldn’t be contacting her, especially regarding a personal matter. However, the customers tactic has worked, because op now feels responsible/duty bound to help her.

Listen to your instincts. You didn’t mind listening to her in her hour of need, your husband minded you doing it. Sounds like he’s the one who has overstepped your boundaries here.

That's the impression I'm getting from your posts, please don't let his thoughtlessness overshadow your kindness.

You sound really kind OP but personally I would see this as overstepping boundaries as ultimately she's a client, not a mate. However boundaries vary person to person and if you are okay with it, doesn't matter what anyone else thinks. I would say though regardless, get a new number that you don't give to clients keep the current number as a business mobile number, then you can switch off to clients when you want or need to, wether thats just occasionally or strictly outside business hours, don't be wearing yourself thin.

It was nice if you to talk to her. Something else that you might like to consider is it is very likely you will lose her as a client . She has opened up massively to you. when things turn around for her she might not like that you know as much about her personal life as you do.
this is another reason why business relationships have boundaries
Likw others have suggested it is best if you point her to professionals

He sounds awful. How cold and thoughtless, I would see him differently. It's very kind of you to actually care and help.

Your DH keeps quoting a boundary.
You have given out your personal mobile number with no restrictions. She can’t cross a boundary if you haven’t put any in place.

She obviously felt you were someone she could talk to, she called and asked if you had time to chat. She gave you the opportunity to say no, you didn’t & you were happy to chat to her. Your DH obviously thinks you shouldn’t be her friend/shoulder/confidante, but that’s not his choice, it’s yours.

If you don’t want someone to overstep boundaries, they have to know what those boundaries are.

If you no longer want her to confide in you, guide her towards someone else (Samaritans if needed) but don’t let your DH decide what your boundaries are.

I would back away and seriously consider your client relationship. Your husband is right. The phone call was inappropriate and has crossed a professional boundary. You are not her friend. Why call you?

Reading the OP posts it comes across that the issue is more the DH and his opinions?
If you are happy to listen to this lady and support her then your DH should respect that.
I personally could never turn anyone away who was struggling and in need of someone to listen to them.

This. Definitely this. I know this is going to sound hard but I think you need to be really careful because you can't unknow things and its quite a risk. If she regrets telling you stuff or it gets out and she blames you, you are going to end up in a nasty situation. It will be through your meaning well but you could end up in shit creek. I think saying "she crossed a boundary" is not a very kind way of putting it, and you did let her, but I think there is some truth in what your husband has said....sorry.

She obviously feels you are a friendly ear but I would be really uncomfortable with that and worry you are going to get dragged into all sorts of drama that is nothing to do with you. Cut it off now, treat her just like a customer when she comes in and if she rings again keep it short.

You know I think you did a kind thing. We’re so quick to tell people get support, reach out. She’s done that. You’re away from her family and friendship circles enough to be away from the problems. But have also supported them feeling connected enough to do that. I worked in bridal T times it would happen on the work phone. If you don’t want to carry it on that’s ok too x

I think he’s seen a red flag and wants to protect his wife. This woman has mistaken a friendly client relationship for a friendship. That’s a clear sign of not understanding social boundaries.

That uncomfortable feeling you got at the beginning of the phone call was your instincts warning you.

It's not up to your DH what your boundaries are, OP - tbh I think he's doing quite a bit of overstepping there himself.

I didn’t mention patient confidentiality, I’m talking about energy, trauma, triggers, and appropriate care. OP has to look after herself and this client, and that doesn’t always look exactly like being available at any moment for any amount of time.