Within the limits of her statutory capacity she may be bound by estoppel like a person of full capacity.1 Thus a deed by a married woman of lands devised to her estops her from setting up an after-acquired title.2 So if she ostensibly borrows money, the fact that she indorses the check to her husband does not relieve her from liability, though she could not act as his surety.3 If she signs the instrument first and represents that she is the principal thereon she is estopped from avoiding liability by claiming to be surety.4 She is not bound by estoppel in instruments outside her statutory capacity. So where by statute she cannot mortgage her property for the debt of her husband, she is not estopped to deny the validity of such mortgage,5 nor is she estopped by joining in her husband's deed of her property, releasing dower therein as if it were his.6 Thus if she has no capacity to make a covenant of warranty she is not estopped to set up an after-acquired title in realty conveyed by her by deed containing such covenant.7 However, if she has agreed to a separation, the written agreement for which is not acknowledged by her as' required by statute, but which is immediately performed, she cannot retain what she has received under such contract and claim the dower released by such defective contract.8 Mere delay in giving notice of the fact that an instrument is a forgery has been held not to estop her.9