English Bull cross that's already showing problematic behaviour?
No. Definitely don't take it. Especially from a dodgy breeder, and when you have no idea what it's crossed with.
I've known a couple of English Bulls and although they were OK in the house with anyone who had been let in, you had to be VERY careful with them both around other dogs - one had to be kept on the lead at all times when out of the garden. Their gardens had to be very secure, and exercising them was a nightmare TBH.
One of my vets refused to treat English Bulls at all, because of his experiences with them. Yes we all know that the dogs are the way they are because of the owners - but unfortunately a certain type of people tend to get bulldogs of various types.
English Bulls are stubborn, strong willed, and require constant consistent training. They can't be left alone for long; can be hard to train and dominant; and need correct early socialisation (which this one clearly hasn't had). They're not a dog for inexperienced owners.
TBH, I've had my own dogs, known English Bulls personally, and I wouldn't take on this dog - it's of unknown age, unknown temperament, unknown background and it's already showing problematic behaviour. It's not a breed for the inexperienced, and definitely not a breed for a reluctant owner.
It sounds like OP and her household are not in a position to meet the needs of this dog - they don't have the time, experience or ability to deal with it.
Taking on a dog like this, when you know you are not capable of meeting it's needs is a folly, and will do more harm than good to the dog. Because if you can't meet the dogs needs, then it's not going to be a successful rehoming - and that will mean the dog ends up needing to be rehomed again. Being shunted from one home to another, is not good the dog - it'd be in the dogs best interest to be rehomed correctly the first time with experienced owners who understand the breed and are capable of meeting it's needs. And that's clearly not the OP.